820640464 has 40 divisors (see below), whose sum is σ = 1866253568. Its totient is φ = 342195840.

The previous prime is 820640383. The next prime is 820640497. The reversal of 820640464 is 464046028.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94872 + ... + 103159.

Almost surely, 2^820640464 is an apocalyptic number.

It is an amenable number.

820640464 is an abundant number, since it is smaller than the sum of its proper divisors (1045613104).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820640464 is a wasteful number, since it uses less digits than its factorization.

820640464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198083 (or 198077 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 34.

The square root of 820640464 is about 28646.8229303007. The cubic root of 820640464 is about 936.2337850778.

The spelling of 820640464 in words is "eight hundred twenty million, six hundred forty thousand, four hundred sixty-four".