21641750155 has 8 divisors (see below), whose sum is σ = 25971145200. Its totient is φ = 17312703456.

The previous prime is 21641750149. The next prime is 21641750171. The reversal of 21641750155 is 55105714612.

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

It is a cyclic number.

It is not a de Polignac number, because 21641750155 - 2⁷ = 21641750027 is a prime.

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, 78076 + ... + 222214.

It is an arithmetic number, because the mean of its divisors is an integer number (3246393150).

Almost surely, 2^21641750155 is an apocalyptic number.

21641750155 is a deficient number, since it is larger than the sum of its proper divisors (4329395045).

21641750155 is a wasteful number, since it uses less digits than its factorization.

21641750155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174173.

The product of its (nonzero) digits is 42000, while the sum is 37.

The spelling of 21641750155 in words is "twenty-one billion, six hundred forty-one million, seven hundred fifty thousand, one hundred fifty-five".