21168372 has 24 divisors (see below), whose sum is σ = 51541056. Its totient is φ = 6749248.

The previous prime is 21168331. The next prime is 21168373. The reversal of 21168372 is 27386112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21168373) 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, 38073 + ... + 38624.

It is an arithmetic number, because the mean of its divisors is an integer number (2147544).

Almost surely, 2^21168372 is an apocalyptic number.

It is an amenable number.

21168372 is an abundant number, since it is smaller than the sum of its proper divisors (30372684).

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

21168372 is a wasteful number, since it uses less digits than its factorization.

21168372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76727 (or 76725 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 21168372 is about 4600.9099100069. The cubic root of 21168372 is about 276.6277979621.

It can be divided in two parts, 21168 and 372, that multiplied together give a triangular number (7874496 = T₃₉₆₈).

The spelling of 21168372 in words is "twenty-one million, one hundred sixty-eight thousand, three hundred seventy-two".