21645342424 has 32 divisors (see below), whose sum is σ = 40826600640. Its totient is φ = 10758420000.

The previous prime is 21645342391. The next prime is 21645342427. The reversal of 21645342424 is 42424354612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21645342427) 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, 1039879 + ... + 1060489.

It is an arithmetic number, because the mean of its divisors is an integer number (1275831270).

Almost surely, 2^21645342424 is an apocalyptic number.

It is an amenable number.

21645342424 is a deficient number, since it is larger than the sum of its proper divisors (19181258216).

21645342424 is a wasteful number, since it uses less digits than its factorization.

21645342424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21391 (or 21387 counting only the distinct ones).

The product of its digits is 184320, while the sum is 37.

The spelling of 21645342424 in words is "twenty-one billion, six hundred forty-five million, three hundred forty-two thousand, four hundred twenty-four".