21142735836 has 12 divisors (see below), whose sum is σ = 49333050312. Its totient is φ = 7047578608.

The previous prime is 21142735769. The next prime is 21142735921. The reversal of 21142735836 is 63853724112.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 880947315 + ... + 880947338.

It is an arithmetic number, because the mean of its divisors is an integer number (4111087526).

Almost surely, 2^21142735836 is an apocalyptic number.

It is an amenable number.

21142735836 is an abundant number, since it is smaller than the sum of its proper divisors (28190314476).

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

21142735836 is a wasteful number, since it uses less digits than its factorization.

21142735836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1761894660 (or 1761894658 counting only the distinct ones).

The product of its digits is 241920, while the sum is 42.

The spelling of 21142735836 in words is "twenty-one billion, one hundred forty-two million, seven hundred thirty-five thousand, eight hundred thirty-six".