21835139924 has 24 divisors (see below), whose sum is σ = 41330561160. Its totient is φ = 10033743744.

The previous prime is 21835139873. The next prime is 21835139927. The reversal of 21835139924 is 42993153812.

It can be written as a sum of positive squares in 4 ways, for example, as 105431824 + 21729708100 = 10268^2 + 147410^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21835139927) 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, 904919 + ... + 928734.

It is an arithmetic number, because the mean of its divisors is an integer number (1722106715).

Almost surely, 2^21835139924 is an apocalyptic number.

It is an amenable number.

21835139924 is a deficient number, since it is larger than the sum of its proper divisors (19495421236).

21835139924 is a wasteful number, since it uses less digits than its factorization.

21835139924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1833899 (or 1833897 counting only the distinct ones).

The product of its digits is 466560, while the sum is 47.

The spelling of 21835139924 in words is "twenty-one billion, eight hundred thirty-five million, one hundred thirty-nine thousand, nine hundred twenty-four".