2640388 has 6 divisors (see below), whose sum is σ = 4620686. Its totient is φ = 1320192.

The previous prime is 2640383. The next prime is 2640397. The reversal of 2640388 is 8830462.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 2566404 + 73984 = 1602^2 + 272^2 .

It is not an unprimeable number, because it can be changed into a prime (2640383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330045 + ... + 330052.

2^2640388 is an apocalyptic number.

It is an amenable number.

2640388 is a deficient number, since it is larger than the sum of its proper divisors (1980298).

2640388 is a wasteful number, since it uses less digits than its factorization.

2640388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 660101 (or 660099 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 2640388 is about 1624.9270752868. The cubic root of 2640388 is about 138.2152350873.

The spelling of 2640388 in words is "two million, six hundred forty thousand, three hundred eighty-eight".