6981921690 has 32 divisors (see below), whose sum is σ = 16772939136. Its totient is φ = 1860031680.

The previous prime is 6981921679. The next prime is 6981921701. The reversal of 6981921690 is 961291896.

It is an interprime number because it is at equal distance from previous prime (6981921679) and next prime (6981921701).

It is a super-2 number, since 2×6981921690² = 97494460970584912200, which contains 22 as substring.

It is a Curzon 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, 81937 + ... + 143796.

It is an arithmetic number, because the mean of its divisors is an integer number (524154348).

Almost surely, 2^6981921690 is an apocalyptic number.

6981921690 is an abundant number, since it is smaller than the sum of its proper divisors (9791017446).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6981921690 is a wasteful number, since it uses less digits than its factorization.

6981921690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226774.

The product of its (nonzero) digits is 419904, while the sum is 51.

The square root of 6981921690 is about 83557.8942410590. The cubic root of 6981921690 is about 1911.2829743497.

The spelling of 6981921690 in words is "six billion, nine hundred eighty-one million, nine hundred twenty-one thousand, six hundred ninety".