71663731 has 2 divisors, whose sum is σ = 71663732. Its totient is φ = 71663730.

The previous prime is 71663717. The next prime is 71663743. The reversal of 71663731 is 13736617.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 71663731 - 2¹⁵ = 71630963 is a prime.

It is a super-2 number, since 2×71663731² = 10271380681680722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (71663831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35831865 + 35831866.

It is an arithmetic number, because the mean of its divisors is an integer number (35831866).

Almost surely, 2^71663731 is an apocalyptic number.

71663731 is a deficient number, since it is larger than the sum of its proper divisors (1).

71663731 is an equidigital number, since it uses as much as digits as its factorization.

71663731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15876, while the sum is 34.

The square root of 71663731 is about 8465.4433433814. The cubic root of 71663731 is about 415.3680984314.

The spelling of 71663731 in words is "seventy-one million, six hundred sixty-three thousand, seven hundred thirty-one".