101515518225 has 81 divisors (see below), whose sum is σ = 199961414107. Its totient is φ = 49194156000.

The previous prime is 101515518217. The next prime is 101515518233. The reversal of 101515518225 is 522815515101.

It is a happy number.

The square root of 101515518225 is 318615.

It is a perfect power (a square), and thus also a powerful number.

101515518225 is a `hidden beast` number, since 1 + 0 + 1 + 5 + 1 + 551 + 82 + 25 = 666.

It is an interprime number because it is at equal distance from previous prime (101515518217) and next prime (101515518233).

It can be written as a sum of positive squares in only one way, i.e., 36545586561 + 64969931664 = 191169^2 + 254892^2 .

It is not a de Polignac number, because 101515518225 - 2³ = 101515518217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 101515518225.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 52570510 + ... + 52572440.

Almost surely, 2^101515518225 is an apocalyptic number.

101515518225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

101515518225 is the 318615-th square number.

101515518225 is the 159308-th centered octagonal number.

It is an amenable number.

101515518225 is a deficient number, since it is larger than the sum of its proper divisors (98445895882).

101515518225 is an equidigital number, since it uses as much as digits as its factorization.

101515518225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3900 (or 1950 counting only the distinct ones).

The product of its (nonzero) digits is 20000, while the sum is 36.

Multiplying 101515518225 by its sum of digits (36), we get a square (3654558656100 = 1911690²).

The spelling of 101515518225 in words is "one hundred one billion, five hundred fifteen million, five hundred eighteen thousand, two hundred twenty-five".