1640764 has 12 divisors (see below), whose sum is σ = 3022600. Its totient is φ = 777168.

The previous prime is 1640761. The next prime is 1640773. The reversal of 1640764 is 4670461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640761) 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, 10719 + ... + 10870.

2^1640764 is an apocalyptic number.

It is an amenable number.

1640764 is a deficient number, since it is larger than the sum of its proper divisors (1381836).

1640764 is a wasteful number, since it uses less digits than its factorization.

1640764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21612 (or 21610 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 1640764 is about 1280.9231046398. The cubic root of 1640764 is about 117.9456802556.

It can be divided in two parts, 16407 and 64, that added together give a triangular number (16471 = T₁₈₁).

The spelling of 1640764 in words is "one million, six hundred forty thousand, seven hundred sixty-four".