640292 has 6 divisors (see below), whose sum is σ = 1120518. Its totient is φ = 320144.

The previous prime is 640279. The next prime is 640303. The reversal of 640292 is 292046.

It can be written as a sum of positive squares in only one way, i.e., 541696 + 98596 = 736^2 + 314^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640292.

It is an unprimeable number.

640292 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80033 + ... + 80040.

It is an arithmetic number, because the mean of its divisors is an integer number (186753).

2⁶⁴⁰²⁹² is an apocalyptic number.

It is an amenable number.

640292 is a deficient number, since it is larger than the sum of its proper divisors (480226).

640292 is a wasteful number, since it uses less digits than its factorization.

640292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160077 (or 160075 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 640292 is about 800.1824791883. The cubic root of 640292 is about 86.1904917529.

The spelling of 640292 in words is "six hundred forty thousand, two hundred ninety-two".