6620690 has 16 divisors (see below), whose sum is σ = 11995992. Its totient is φ = 2630784.

The previous prime is 6620689. The next prime is 6620693. The reversal of 6620690 is 960266.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5851561 + 769129 = 2419^2 + 877^2 .

It is a super-2 number, since 2×6620690² = 87667072152200, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6620693) 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, 539 + ... + 3678.

Almost surely, 2^6620690 is an apocalyptic number.

6620690 is a deficient number, since it is larger than the sum of its proper divisors (5375302).

6620690 is a wasteful number, since it uses less digits than its factorization.

6620690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4381.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 6620690 is about 2573.0701506177. The cubic root of 6620690 is about 187.7735503433.

The spelling of 6620690 in words is "six million, six hundred twenty thousand, six hundred ninety".