815219381025 has 81 divisors (see below), whose sum is σ = 1698737632371. Its totient is φ = 372628378080.

The previous prime is 815219380903. The next prime is 815219381057. The reversal of 815219381025 is 520183912518.

The square root of 815219381025 is 902895.

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

815219381025 is a `hidden beast` number, since 8 + 1 + 521 + 93 + 8 + 10 + 25 = 666.

It can be written as a sum of positive squares in only one way, i.e., 293478977169 + 521740403856 = 541737^2 + 722316^2 .

It is not a de Polignac number, because 815219381025 - 2¹¹ = 815219378977 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 94799676 + ... + 94808274.

Almost surely, 2^815219381025 is an apocalyptic number.

815219381025 is the 902895-th square number.

815219381025 is the 451448-th centered octagonal number.

It is an amenable number.

815219381025 is an abundant number, since it is smaller than the sum of its proper divisors (883518251346).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

815219381025 is an frugal number, since it uses more digits than its factorization.

815219381025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17228 (or 8614 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 45.

The spelling of 815219381025 in words is "eight hundred fifteen billion, two hundred nineteen million, three hundred eighty-one thousand, twenty-five".