21054757915 has 8 divisors (see below), whose sum is σ = 26136941040. Its totient is φ = 16262985312.

The previous prime is 21054757891. The next prime is 21054757937. The reversal of 21054757915 is 51975745012.

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 21054757915 - 2¹⁵ = 21054725147 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72602469 + ... + 72602758.

It is an arithmetic number, because the mean of its divisors is an integer number (3267117630).

Almost surely, 2^21054757915 is an apocalyptic number.

21054757915 is a deficient number, since it is larger than the sum of its proper divisors (5082183125).

21054757915 is a wasteful number, since it uses less digits than its factorization.

21054757915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145205261.

The product of its (nonzero) digits is 441000, while the sum is 46.

The spelling of 21054757915 in words is "twenty-one billion, fifty-four million, seven hundred fifty-seven thousand, nine hundred fifteen".