231771431 has 2 divisors, whose sum is σ = 231771432. Its totient is φ = 231771430.

The previous prime is 231771409. The next prime is 231771457. The reversal of 231771431 is 134177132.

It is a happy number.

231771431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 231771431 - 2²² = 227577127 is a prime.

It is a super-2 number, since 2×231771431² = 107435992455575522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 231771394 and 231771403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231771461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115885715 + 115885716.

It is an arithmetic number, because the mean of its divisors is an integer number (115885716).

Almost surely, 2^231771431 is an apocalyptic number.

231771431 is a deficient number, since it is larger than the sum of its proper divisors (1).

231771431 is an equidigital number, since it uses as much as digits as its factorization.

231771431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3528, while the sum is 29.

The square root of 231771431 is about 15224.0412177582. The cubic root of 231771431 is about 614.2615067671.

The spelling of 231771431 in words is "two hundred thirty-one million, seven hundred seventy-one thousand, four hundred thirty-one".