1640626 has 16 divisors (see below), whose sum is σ = 2683800. Its totient is φ = 747648.

The previous prime is 1640623. The next prime is 1640633. The reversal of 1640626 is 6260461.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 540225 + 1100401 = 735^2 + 1049^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1640626.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1960 + ... + 2668.

2^1640626 is an apocalyptic number.

1640626 is a deficient number, since it is larger than the sum of its proper divisors (1043174).

1640626 is a wasteful number, since it uses less digits than its factorization.

1640626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 813.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 1640626 is about 1280.8692361049. The cubic root of 1640626 is about 117.9423734708.

The spelling of 1640626 in words is "one million, six hundred forty thousand, six hundred twenty-six".