21436687724 has 12 divisors (see below), whose sum is σ = 37515311064. Its totient is φ = 10718027424.

The previous prime is 21436687673. The next prime is 21436687747. The reversal of 21436687724 is 42778663412.

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, 141944 + ... + 251040.

It is an arithmetic number, because the mean of its divisors is an integer number (3126275922).

Almost surely, 2^21436687724 is an apocalyptic number.

It is an amenable number.

21436687724 is a deficient number, since it is larger than the sum of its proper divisors (16078623340).

21436687724 is a wasteful number, since it uses less digits than its factorization.

21436687724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158224 (or 158222 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 50.

The spelling of 21436687724 in words is "twenty-one billion, four hundred thirty-six million, six hundred eighty-seven thousand, seven hundred twenty-four".