225015521661 has 24 divisors (see below), whose sum is σ = 372776124864. Its totient is φ = 128122706880.

The previous prime is 225015521579. The next prime is 225015521671. The reversal of 225015521661 is 166125510522.

225015521661 is a `hidden beast` number, since 22 + 50 + 1 + 5 + 521 + 6 + 61 = 666.

It is not a de Polignac number, because 225015521661 - 2⁹ = 225015521149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225015521671) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6337591 + ... + 6372996.

It is an arithmetic number, because the mean of its divisors is an integer number (15532338536).

Almost surely, 2^225015521661 is an apocalyptic number.

225015521661 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

225015521661 is a deficient number, since it is larger than the sum of its proper divisors (147760603203).

225015521661 is a wasteful number, since it uses less digits than its factorization.

225015521661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12710881 (or 12710878 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 36.

The spelling of 225015521661 in words is "two hundred twenty-five billion, fifteen million, five hundred twenty-one thousand, six hundred sixty-one".