661527 has 10 divisors (see below), whose sum is σ = 988328. Its totient is φ = 440964.

The previous prime is 661517. The next prime is 661541. The reversal of 661527 is 725166.

It is not a de Polignac number, because 661527 - 2¹⁰ = 660503 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661527.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661517) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4003 + ... + 4164.

2⁶⁶¹⁵²⁷ is an apocalyptic number.

661527 is a deficient number, since it is larger than the sum of its proper divisors (326801).

661527 is an equidigital number, since it uses as much as digits as its factorization.

661527 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8179 (or 8170 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 661527 is about 813.3431010342. The cubic root of 661527 is about 87.1329714538.

The spelling of 661527 in words is "six hundred sixty-one thousand, five hundred twenty-seven".