21121310236646 has 32 divisors (see below), whose sum is σ = 32230946239200. Its totient is φ = 10377984314880.

The previous prime is 21121310236601. The next prime is 21121310236703. The reversal of 21121310236646 is 64663201312112.

It is a super-2 number, since 2×21121310236646² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 644142020 + ... + 644174808.

It is an arithmetic number, because the mean of its divisors is an integer number (1007217069975).

Almost surely, 2^{21121310236646} is an apocalyptic number.

21121310236646 is a deficient number, since it is larger than the sum of its proper divisors (11109636002554).

21121310236646 is a wasteful number, since it uses less digits than its factorization.

21121310236646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37544.

The product of its (nonzero) digits is 62208, while the sum is 38.

Adding to 21121310236646 its reverse (64663201312112), we get a palindrome (85784511548758).

The spelling of 21121310236646 in words is "twenty-one trillion, one hundred twenty-one billion, three hundred ten million, two hundred thirty-six thousand, six hundred forty-six".