21890072 has 16 divisors (see below), whose sum is σ = 41607240. Its totient is φ = 10794816.

The previous prime is 21890047. The next prime is 21890083. The reversal of 21890072 is 27009812.

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 in 3 ways as a sum of consecutive naturals, for example, 18158 + ... + 19325.

Almost surely, 2^21890072 is an apocalyptic number.

It is an amenable number.

21890072 is a deficient number, since it is larger than the sum of its proper divisors (19717168).

21890072 is a wasteful number, since it uses less digits than its factorization.

21890072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37562 (or 37558 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 21890072 is about 4678.6827205956. The cubic root of 21890072 is about 279.7364526967.

Adding to 21890072 its reverse (27009812), we get a palindrome (48899884).

The spelling of 21890072 in words is "twenty-one million, eight hundred ninety thousand, seventy-two".