155202561 has 20 divisors (see below), whose sum is σ = 234461700. Its totient is φ = 102301056.

The previous prime is 155202539. The next prime is 155202617. The reversal of 155202561 is 165202551.

It can be written as a sum of positive squares in 2 ways, for example, as 27625536 + 127577025 = 5256^2 + 11295^2 .

It is not a de Polignac number, because 155202561 - 2⁷ = 155202433 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (155202511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3556 + ... + 17973.

It is an arithmetic number, because the mean of its divisors is an integer number (11723085).

Almost surely, 2^155202561 is an apocalyptic number.

It is an amenable number.

155202561 is a deficient number, since it is larger than the sum of its proper divisors (79259139).

155202561 is an equidigital number, since it uses as much as digits as its factorization.

155202561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21630 (or 21621 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The square root of 155202561 is about 12458.0319874369. The cubic root of 155202561 is about 537.4024323355.

It can be divided in two parts, 15520 and 2561, that added together give a palindrome (18081).

The spelling of 155202561 in words is "one hundred fifty-five million, two hundred two thousand, five hundred sixty-one".