21372044 has 6 divisors (see below), whose sum is σ = 37401084. Its totient is φ = 10686020.

The previous prime is 21372041. The next prime is 21372047. The reversal of 21372044 is 44027312.

It is an interprime number because it is at equal distance from previous prime (21372041) and next prime (21372047).

It is not an unprimeable number, because it can be changed into a prime (21372041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2671502 + ... + 2671509.

It is an arithmetic number, because the mean of its divisors is an integer number (6233514).

Almost surely, 2^21372044 is an apocalyptic number.

It is an amenable number.

21372044 is a deficient number, since it is larger than the sum of its proper divisors (16029040).

21372044 is a wasteful number, since it uses less digits than its factorization.

21372044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5343015 (or 5343013 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 21372044 is about 4622.9908068262. The cubic root of 21372044 is about 277.5121613586.

Adding to 21372044 its reverse (44027312), we get a palindrome (65399356).

The spelling of 21372044 in words is "twenty-one million, three hundred seventy-two thousand, forty-four".