213153731 has 4 divisors (see below), whose sum is σ = 243604272. Its totient is φ = 182703192.

The previous prime is 213153697. The next prime is 213153749. The reversal of 213153731 is 137351312.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 213153731 - 2²⁶ = 146044867 is a prime.

It is a super-2 number, since 2×213153731² = 90869026078440722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 213153731.

It is not an unprimeable number, because it can be changed into a prime (213153631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15225260 + ... + 15225273.

It is an arithmetic number, because the mean of its divisors is an integer number (60901068).

Almost surely, 2^213153731 is an apocalyptic number.

213153731 is a deficient number, since it is larger than the sum of its proper divisors (30450541).

213153731 is an equidigital number, since it uses as much as digits as its factorization.

213153731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30450540.

The product of its digits is 1890, while the sum is 26.

The square root of 213153731 is about 14599.7853066406. The cubic root of 213153731 is about 597.3529043900.

The spelling of 213153731 in words is "two hundred thirteen million, one hundred fifty-three thousand, seven hundred thirty-one".