661437 has 12 divisors (see below), whose sum is σ = 1092000. Its totient is φ = 377928.

The previous prime is 661421. The next prime is 661439. The reversal of 661437 is 734166.

It is not a de Polignac number, because 661437 - 2⁴ = 661421 is a prime.

661437 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 661437.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661439) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5187 + ... + 5312.

It is an arithmetic number, because the mean of its divisors is an integer number (91000).

2⁶⁶¹⁴³⁷ is an apocalyptic number.

It is an amenable number.

661437 is a deficient number, since it is larger than the sum of its proper divisors (430563).

661437 is a wasteful number, since it uses less digits than its factorization.

661437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10512 (or 10509 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 661437 is about 813.2877719479. The cubic root of 661437 is about 87.1290198272.

The spelling of 661437 in words is "six hundred sixty-one thousand, four hundred thirty-seven".