21345726388 has 48 divisors (see below), whose sum is σ = 46424448000. Its totient is φ = 8377330176.

The previous prime is 21345726373. The next prime is 21345726421. The reversal of 21345726388 is 88362754312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 588388 + ... + 623611.

It is an arithmetic number, because the mean of its divisors is an integer number (967176000).

Almost surely, 2^21345726388 is an apocalyptic number.

21345726388 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21345726388 is an abundant number, since it is smaller than the sum of its proper divisors (25078721612).

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

21345726388 is a wasteful number, since it uses less digits than its factorization.

21345726388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1212064 (or 1212062 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 49.

The spelling of 21345726388 in words is "twenty-one billion, three hundred forty-five million, seven hundred twenty-six thousand, three hundred eighty-eight".