21371672 has 16 divisors (see below), whose sum is σ = 45796560. Its totient is φ = 9159264.

The previous prime is 21371663. The next prime is 21371683. The reversal of 21371672 is 27617312.

It is a congruent number.

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, 190763 + ... + 190874.

It is an arithmetic number, because the mean of its divisors is an integer number (2862285).

Almost surely, 2^21371672 is an apocalyptic number.

It is an amenable number.

21371672 is an abundant number, since it is smaller than the sum of its proper divisors (24424888).

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

21371672 is a wasteful number, since it uses less digits than its factorization.

21371672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381650 (or 381646 counting only the distinct ones).

The product of its digits is 3528, while the sum is 29.

The square root of 21371672 is about 4622.9505729566. The cubic root of 21371672 is about 277.5105512315.

Adding to 21371672 its reverse (27617312), we get a palindrome (48988984).

The spelling of 21371672 in words is "twenty-one million, three hundred seventy-one thousand, six hundred seventy-two".