21506731055010 has 144 divisors (see below), whose sum is σ = 60067478086200. Its totient is φ = 5537364747264.

The previous prime is 21506731054979. The next prime is 21506731055053. The reversal of 21506731055010 is 1055013760512.

It is a happy number.

21506731055010 is a `hidden beast` number, since 2 + 1 + 5 + 0 + 67 + 31 + 0 + 550 + 10 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 18366615925641 + 3140115129369 = 4285629^2 + 1772037^2 .

It is a super-2 number, since 2×21506731055010² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3748975 + ... + 7554354.

Almost surely, 2^{21506731055010} is an apocalyptic number.

21506731055010 is an abundant number, since it is smaller than the sum of its proper divisors (38560747031190).

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

21506731055010 is an equidigital number, since it uses as much as digits as its factorization.

21506731055010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11303389 (or 11303368 counting only the distinct ones).

The product of its (nonzero) digits is 31500, while the sum is 36.

The spelling of 21506731055010 in words is "twenty-one trillion, five hundred six billion, seven hundred thirty-one million, fifty-five thousand, ten".