21406993374 has 16 divisors (see below), whose sum is σ = 46107370512. Its totient is φ = 6586767168.

The previous prime is 21406993373. The next prime is 21406993409. The reversal of 21406993374 is 47339960412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21406993373) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137224239 + ... + 137224394.

It is an arithmetic number, because the mean of its divisors is an integer number (2881710657).

Almost surely, 2^21406993374 is an apocalyptic number.

21406993374 is an abundant number, since it is smaller than the sum of its proper divisors (24700377138).

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

21406993374 is a wasteful number, since it uses less digits than its factorization.

21406993374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274448651.

The product of its (nonzero) digits is 979776, while the sum is 48.

The spelling of 21406993374 in words is "twenty-one billion, four hundred six million, nine hundred ninety-three thousand, three hundred seventy-four".