21180993534 has 16 divisors (see below), whose sum is σ = 47068874640. Its totient is φ = 7060331160.

The previous prime is 21180993529. The next prime is 21180993553. The reversal of 21180993534 is 43539908112.

It is a happy number.

21180993534 is a `hidden beast` number, since 21 + 1 + 8 + 0 + 9 + 93 + 534 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21180993534.

It is a congruent number.

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, 196120257 + ... + 196120364.

It is an arithmetic number, because the mean of its divisors is an integer number (2941804665).

Almost surely, 2^21180993534 is an apocalyptic number.

21180993534 is an abundant number, since it is smaller than the sum of its proper divisors (25887881106).

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

21180993534 is a wasteful number, since it uses less digits than its factorization.

21180993534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392240632 (or 392240626 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The spelling of 21180993534 in words is "twenty-one billion, one hundred eighty million, nine hundred ninety-three thousand, five hundred thirty-four".