21130345505644 has 24 divisors (see below), whose sum is σ = 39153662467920. Its totient is φ = 9943596711936.

The previous prime is 21130345505579. The next prime is 21130345505681. The reversal of 21130345505644 is 44650554303112.

It is a self number, because there is not a number n which added to its sum of digits gives 21130345505644.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5928879 + ... + 8798425.

It is an arithmetic number, because the mean of its divisors is an integer number (1631402602830).

Almost surely, 2^{21130345505644} is an apocalyptic number.

It is an amenable number.

21130345505644 is a deficient number, since it is larger than the sum of its proper divisors (18023316962276).

21130345505644 is a wasteful number, since it uses less digits than its factorization.

21130345505644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2977857 (or 2977855 counting only the distinct ones).

The product of its (nonzero) digits is 864000, while the sum is 43.

Adding to 21130345505644 its reverse (44650554303112), we get a palindrome (65780899808756).

The spelling of 21130345505644 in words is "twenty-one trillion, one hundred thirty billion, three hundred forty-five million, five hundred five thousand, six hundred forty-four".