231545021 has 4 divisors (see below), whose sum is σ = 231640032. Its totient is φ = 231450012.

The previous prime is 231545011. The next prime is 231545029. The reversal of 231545021 is 120545132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 231545021 - 2¹⁴ = 231528637 is a prime.

It is a super-2 number, since 2×231545021² = 107226193499780882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231545029) 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, 43751 + ... + 48756.

It is an arithmetic number, because the mean of its divisors is an integer number (57910008).

Almost surely, 2^231545021 is an apocalyptic number.

It is an amenable number.

231545021 is a deficient number, since it is larger than the sum of its proper divisors (95011).

231545021 is an equidigital number, since it uses as much as digits as its factorization.

231545021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95010.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 231545021 is about 15216.6034646369. The cubic root of 231545021 is about 614.0614242150.

The spelling of 231545021 in words is "two hundred thirty-one million, five hundred forty-five thousand, twenty-one".