213231731 has 8 divisors (see below), whose sum is σ = 228496464. Its totient is φ = 198269440.

The previous prime is 213231719. The next prime is 213231749. The reversal of 213231731 is 137132312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213231731 is a prime.

It is a super-2 number, since 2×213231731² = 90935542210512722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213231697 and 213231706.

It is not an unprimeable number, because it can be changed into a prime (213231701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74150 + ... + 76971.

It is an arithmetic number, because the mean of its divisors is an integer number (28562058).

Almost surely, 2^213231731 is an apocalyptic number.

213231731 is a deficient number, since it is larger than the sum of its proper divisors (15264733).

213231731 is a wasteful number, since it uses less digits than its factorization.

213231731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151221.

The product of its digits is 756, while the sum is 23.

The square root of 213231731 is about 14602.4563344665. The cubic root of 213231731 is about 597.4257592322.

The spelling of 213231731 in words is "two hundred thirteen million, two hundred thirty-one thousand, seven hundred thirty-one".