667520431 has 2 divisors, whose sum is σ = 667520432. Its totient is φ = 667520430.

The previous prime is 667520429. The next prime is 667520449. The reversal of 667520431 is 134025766.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 667520431 - 2¹ = 667520429 is a prime.

It is a super-2 number, since 2×667520431² = 891167051604851522, which contains 22 as substring.

Together with 667520429, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667520401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333760215 + 333760216.

It is an arithmetic number, because the mean of its divisors is an integer number (333760216).

Almost surely, 2^667520431 is an apocalyptic number.

667520431 is a deficient number, since it is larger than the sum of its proper divisors (1).

667520431 is an equidigital number, since it uses as much as digits as its factorization.

667520431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 667520431 is about 25836.4167600695. The cubic root of 667520431 is about 873.9532215798.

The spelling of 667520431 in words is "six hundred sixty-seven million, five hundred twenty thousand, four hundred thirty-one".