21190872 has 16 divisors (see below), whose sum is σ = 52977240. Its totient is φ = 7063616.

The previous prime is 21190867. The next prime is 21190879. The reversal of 21190872 is 27809112.

It is a super-2 number, since 2×21190872² = 898106112240768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21190879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 441453 + ... + 441500.

Almost surely, 2^21190872 is an apocalyptic number.

It is an amenable number.

21190872 is an abundant number, since it is smaller than the sum of its proper divisors (31786368).

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

21190872 is a wasteful number, since it uses less digits than its factorization.

21190872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 882962 (or 882958 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 21190872 is about 4603.3544291093. The cubic root of 21190872 is about 276.7257730849.

Adding to 21190872 its reverse (27809112), we get a palindrome (48999984).

The spelling of 21190872 in words is "twenty-one million, one hundred ninety thousand, eight hundred seventy-two".