21155763426 has 24 divisors (see below), whose sum is σ = 49219531920. Its totient is φ = 6044503752.

The previous prime is 21155763413. The next prime is 21155763439. The reversal of 21155763426 is 62436755112.

It is an interprime number because it is at equal distance from previous prime (21155763413) and next prime (21155763439).

It is a super-2 number, since 2×21155763426² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35978896 + ... + 35979483.

It is an arithmetic number, because the mean of its divisors is an integer number (2050813830).

Almost surely, 2^21155763426 is an apocalyptic number.

21155763426 is an abundant number, since it is smaller than the sum of its proper divisors (28063768494).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21155763426 is a wasteful number, since it uses less digits than its factorization.

21155763426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71958398 (or 71958391 counting only the distinct ones).

The product of its digits is 302400, while the sum is 42.

The spelling of 21155763426 in words is "twenty-one billion, one hundred fifty-five million, seven hundred sixty-three thousand, four hundred twenty-six".