715661 has 4 divisors (see below), whose sum is σ = 724800. Its totient is φ = 706524.

The previous prime is 715657. The next prime is 715679. The reversal of 715661 is 166517.

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, and also an emirpimes, since its reverse is a distinct semiprime: 166517 = 13 ⋅12809.

It is a cyclic number.

It is not a de Polignac number, because 715661 - 2² = 715657 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 715661.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 715661.

It is not an unprimeable number, because it can be changed into a prime (715621) 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, 4451 + ... + 4608.

It is an arithmetic number, because the mean of its divisors is an integer number (181200).

2⁷¹⁵⁶⁶¹ is an apocalyptic number.

It is an amenable number.

715661 is a deficient number, since it is larger than the sum of its proper divisors (9139).

715661 is an equidigital number, since it uses as much as digits as its factorization.

715661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9138.

The product of its digits is 1260, while the sum is 26.

The square root of 715661 is about 845.9674934653. The cubic root of 715661 is about 89.4476874573.

The spelling of 715661 in words is "seven hundred fifteen thousand, six hundred sixty-one".