6401690 has 16 divisors (see below), whose sum is σ = 12201192. Its totient is φ = 2409984.

The previous prime is 6401687. The next prime is 6401713. The reversal of 6401690 is 961046.

It can be written as a sum of positive squares in 4 ways, for example, as 6255001 + 146689 = 2501^2 + 383^2 .

It is a super-2 number, since 2×6401690² = 81963269712200, which contains 22 as substring.

It is an Ulam 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, 18659 + ... + 18998.

Almost surely, 2^6401690 is an apocalyptic number.

6401690 is a deficient number, since it is larger than the sum of its proper divisors (5799502).

6401690 is a wasteful number, since it uses less digits than its factorization.

6401690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37681.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 6401690 is about 2530.1561216652. The cubic root of 6401690 is about 185.6798941669.

It can be divided in two parts, 640 and 1690, that multiplied together give a square (1081600 = 1040²).

The spelling of 6401690 in words is "six million, four hundred one thousand, six hundred ninety".