21122615560 has 16 divisors (see below), whose sum is σ = 47525885100. Its totient is φ = 8449046208.

The previous prime is 21122615539. The next prime is 21122615567. The reversal of 21122615560 is 6551622112.

It can be written as a sum of positive squares in 2 ways, for example, as 20798831524 + 323784036 = 144218^2 + 17994^2 .

It is a super-2 number, since 2×21122615560² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21122615567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264032655 + ... + 264032734.

Almost surely, 2^21122615560 is an apocalyptic number.

21122615560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21122615560 is an abundant number, since it is smaller than the sum of its proper divisors (26403269540).

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

21122615560 is a wasteful number, since it uses less digits than its factorization.

21122615560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528065400 (or 528065396 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 31.

The spelling of 21122615560 in words is "twenty-one billion, one hundred twenty-two million, six hundred fifteen thousand, five hundred sixty".