21621412157651 has 8 divisors (see below), whose sum is σ = 23071153565520. Its totient is φ = 20202847984512.

The previous prime is 21621412157633. The next prime is 21621412157663. The reversal of 21621412157651 is 15675121412612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21621412157651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21621412157351) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7794307250 + ... + 7794310023.

It is an arithmetic number, because the mean of its divisors is an integer number (2883894195690).

Almost surely, 2^{21621412157651} is an apocalyptic number.

21621412157651 is a deficient number, since it is larger than the sum of its proper divisors (1449741407869).

21621412157651 is a wasteful number, since it uses less digits than its factorization.

21621412157651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15588617365.

The product of its digits is 201600, while the sum is 44.

The spelling of 21621412157651 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred twelve million, one hundred fifty-seven thousand, six hundred fifty-one".