71501665 has 4 divisors (see below), whose sum is σ = 85802004. Its totient is φ = 57201328.

The previous prime is 71501653. The next prime is 71501713. The reversal of 71501665 is 56610517.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56610517 = 1427 ⋅39671.

It can be written as a sum of positive squares in 2 ways, for example, as 31102929 + 40398736 = 5577^2 + 6356^2 .

It is a cyclic number.

It is not a de Polignac number, because 71501665 - 2⁷ = 71501537 is a prime.

It is a super-2 number, since 2×71501665² = 10224976195544450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7150162 + ... + 7150171.

It is an arithmetic number, because the mean of its divisors is an integer number (21450501).

Almost surely, 2^71501665 is an apocalyptic number.

It is an amenable number.

71501665 is a deficient number, since it is larger than the sum of its proper divisors (14300339).

71501665 is a wasteful number, since it uses less digits than its factorization.

71501665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14300338.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 71501665 is about 8455.8657155847. The cubic root of 71501665 is about 415.0547467331.

The spelling of 71501665 in words is "seventy-one million, five hundred one thousand, six hundred sixty-five".