645942790 has 8 divisors (see below), whose sum is σ = 1162697040. Its totient is φ = 258377112.

The previous prime is 645942749. The next prime is 645942799. The reversal of 645942790 is 97249546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 645942790.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645942799) 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, 32297130 + ... + 32297149.

It is an arithmetic number, because the mean of its divisors is an integer number (145337130).

Almost surely, 2^645942790 is an apocalyptic number.

645942790 is a deficient number, since it is larger than the sum of its proper divisors (516754250).

645942790 is a wasteful number, since it uses less digits than its factorization.

645942790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64594286.

The product of its (nonzero) digits is 544320, while the sum is 46.

The square root of 645942790 is about 25415.4045806869. The cubic root of 645942790 is about 864.4330274981.

The spelling of 645942790 in words is "six hundred forty-five million, nine hundred forty-two thousand, seven hundred ninety".