21157562127 has 8 divisors (see below), whose sum is σ = 30380089264. Its totient is φ = 13020038208.

The previous prime is 21157562123. The next prime is 21157562137. The reversal of 21157562127 is 72126575112.

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

It is not a de Polignac number, because 21157562127 - 2² = 21157562123 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 542501593 = 21157562127 / (2 + 1 + 1 + 5 + 7 + 5 + 6 + 2 + 1 + 2 + 7).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21157562123) by changing a digit.

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, 271250758 + ... + 271250835.

It is an arithmetic number, because the mean of its divisors is an integer number (3797511158).

Almost surely, 2^21157562127 is an apocalyptic number.

21157562127 is a deficient number, since it is larger than the sum of its proper divisors (9222527137).

21157562127 is a wasteful number, since it uses less digits than its factorization.

21157562127 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 542501609.

The product of its digits is 58800, while the sum is 39.

The spelling of 21157562127 in words is "twenty-one billion, one hundred fifty-seven million, five hundred sixty-two thousand, one hundred twenty-seven".