21942993408 has 120 divisors (see below), whose sum is σ = 68001821712. Its totient is φ = 6269405184.

The previous prime is 21942993403. The next prime is 21942993421. The reversal of 21942993408 is 80439924912.

It is not an unprimeable number, because it can be changed into a prime (21942993403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70510 + ... + 221037.

Almost surely, 2^21942993408 is an apocalyptic number.

21942993408 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21942993408 is an abundant number, since it is smaller than the sum of its proper divisors (46058828304).

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

21942993408 is an equidigital number, since it uses as much as digits as its factorization.

21942993408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291582 (or 291559 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 51.

The spelling of 21942993408 in words is "twenty-one billion, nine hundred forty-two million, nine hundred ninety-three thousand, four hundred eight".