21241655631 has 24 divisors (see below), whose sum is σ = 35090209440. Its totient is φ = 12129566976.

The previous prime is 21241655627. The next prime is 21241655657. The reversal of 21241655631 is 13655614212.

21241655631 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 16 + 5 + 5 + 631 = 666.

It is not a de Polignac number, because 21241655631 - 2² = 21241655627 is a prime.

It is a super-2 number, since 2×21241655631² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21241650631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27366 + ... + 207923.

It is an arithmetic number, because the mean of its divisors is an integer number (1462092060).

Almost surely, 2^21241655631 is an apocalyptic number.

21241655631 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21241655631 is a deficient number, since it is larger than the sum of its proper divisors (13848553809).

21241655631 is a wasteful number, since it uses less digits than its factorization.

21241655631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236735 (or 236732 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The spelling of 21241655631 in words is "twenty-one billion, two hundred forty-one million, six hundred fifty-five thousand, six hundred thirty-one".