6491661902 has 32 divisors (see below), whose sum is σ = 10979587584. Its totient is φ = 2853140800.

The previous prime is 6491661893. The next prime is 6491661931. The reversal of 6491661902 is 2091661946.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48002 + ... + 123642.

It is an arithmetic number, because the mean of its divisors is an integer number (343112112).

Almost surely, 2^6491661902 is an apocalyptic number.

6491661902 is a deficient number, since it is larger than the sum of its proper divisors (4487925682).

6491661902 is a wasteful number, since it uses less digits than its factorization.

6491661902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75784.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 6491661902 is about 80570.8502003051. The cubic root of 6491661902 is about 1865.4572358208.

Adding to 6491661902 its sum of digits (44), we get a palindrome (6491661946).

The spelling of 6491661902 in words is "six billion, four hundred ninety-one million, six hundred sixty-one thousand, nine hundred two".