21351631262644 has 12 divisors (see below), whose sum is σ = 38989935349344. Its totient is φ = 10211649734264.

The previous prime is 21351631262603. The next prime is 21351631262699. The reversal of 21351631262644 is 44626213615312.

It is a super-2 number, since 2×21351631262644² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a junction number, because it is equal to n+sod(n) for n = 21351631262594 and 21351631262603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116041474162 + ... + 116041474345.

It is an arithmetic number, because the mean of its divisors is an integer number (3249161279112).

Almost surely, 2^{21351631262644} is an apocalyptic number.

It is an amenable number.

21351631262644 is a deficient number, since it is larger than the sum of its proper divisors (17638304086700).

21351631262644 is a wasteful number, since it uses less digits than its factorization.

21351631262644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232082948534 (or 232082948532 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 46.

Adding to 21351631262644 its reverse (44626213615312), we get a palindrome (65977844877956).

The spelling of 21351631262644 in words is "twenty-one trillion, three hundred fifty-one billion, six hundred thirty-one million, two hundred sixty-two thousand, six hundred forty-four".