815501108601 has 45 divisors (see below), whose sum is σ = 1285952496543. Its totient is φ = 514955802240.

The previous prime is 815501108519. The next prime is 815501108603. The reversal of 815501108601 is 106801105518.

The square root of 815501108601 is 903051.

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

815501108601 is a `hidden beast` number, since 81 + 5 + 501 + 10 + 8 + 60 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 107681766201 + 707819342400 = 328149^2 + 841320^2 .

It is not a de Polignac number, because 815501108601 - 2³¹ = 813353624953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (815501108603) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 154419081 + ... + 154424361.

Almost surely, 2^815501108601 is an apocalyptic number.

815501108601 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

815501108601 is the 903051-st square number.

815501108601 is the 451526-th centered octagonal number.

It is an amenable number.

815501108601 is a deficient number, since it is larger than the sum of its proper divisors (470451387942).

815501108601 is an frugal number, since it uses more digits than its factorization.

815501108601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10612 (or 5303 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 36.

Multiplying 815501108601 by its sum of digits (36), we get a square (29358039909636 = 5418306²).

The spelling of 815501108601 in words is "eight hundred fifteen billion, five hundred one million, one hundred eight thousand, six hundred one".