661937 has 4 divisors (see below), whose sum is σ = 664560. Its totient is φ = 659316.

The previous prime is 661931. The next prime is 661939. The reversal of 661937 is 739166.

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.

It is a cyclic number.

It is not a de Polignac number, because 661937 - 2⁶ = 661873 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (661931) 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, 887 + ... + 1452.

It is an arithmetic number, because the mean of its divisors is an integer number (166140).

2⁶⁶¹⁹³⁷ is an apocalyptic number.

It is an amenable number.

661937 is a deficient number, since it is larger than the sum of its proper divisors (2623).

661937 is a wasteful number, since it uses less digits than its factorization.

661937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2622.

The product of its digits is 6804, while the sum is 32.

The square root of 661937 is about 813.5951081466. The cubic root of 661937 is about 87.1509687744.

The spelling of 661937 in words is "six hundred sixty-one thousand, nine hundred thirty-seven".