213121872 has 30 divisors (see below), whose sum is σ = 596445642. Its totient is φ = 71040576.

The previous prime is 213121871. The next prime is 213121873. The reversal of 213121872 is 278121312.

It is an interprime number because it is at equal distance from previous prime (213121871) and next prime (213121873).

It can be written as a sum of positive squares in only one way, i.e., 179667216 + 33454656 = 13404^2 + 5784^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213121871) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 739863 + ... + 740150.

Almost surely, 2^213121872 is an apocalyptic number.

It is an amenable number.

213121872 is an abundant number, since it is smaller than the sum of its proper divisors (383323770).

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

213121872 is a wasteful number, since it uses less digits than its factorization.

213121872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1480027 (or 1480018 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 213121872 is about 14598.6941881800. The cubic root of 213121872 is about 597.3231418108.

The spelling of 213121872 in words is "two hundred thirteen million, one hundred twenty-one thousand, eight hundred seventy-two".