21167645372 has 6 divisors (see below), whose sum is σ = 37043379408. Its totient is φ = 10583822684.

The previous prime is 21167645363. The next prime is 21167645423. The reversal of 21167645372 is 27354676112.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2645955668 + ... + 2645955675.

It is an arithmetic number, because the mean of its divisors is an integer number (6173896568).

Almost surely, 2^21167645372 is an apocalyptic number.

It is an amenable number.

21167645372 is a deficient number, since it is larger than the sum of its proper divisors (15875734036).

21167645372 is a wasteful number, since it uses less digits than its factorization.

21167645372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5291911347 (or 5291911345 counting only the distinct ones).

The product of its digits is 423360, while the sum is 44.

The spelling of 21167645372 in words is "twenty-one billion, one hundred sixty-seven million, six hundred forty-five thousand, three hundred seventy-two".