6991560 has 48 divisors (see below), whose sum is σ = 22723740. Its totient is φ = 1864320.

The previous prime is 6991553. The next prime is 6991571. The reversal of 6991560 is 651996.

6991560 is a `hidden beast` number, since 6 + 9 + 91 + 560 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6563844 + 427716 = 2562^2 + 654^2 .

It is a super-2 number, since 2×6991560² = 97763822467200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9351 + ... + 10070.

Almost surely, 2^6991560 is an apocalyptic number.

6991560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6991560 is an abundant number, since it is smaller than the sum of its proper divisors (15732180).

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

6991560 is a wasteful number, since it uses less digits than its factorization.

6991560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19438 (or 19431 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 6991560 is about 2644.1558199168. The cubic root of 6991560 is about 191.2162057423.

Subtracting from 6991560 its product of nonzero digits (14580), we obtain a triangular number (6976980 = T₃₇₃₅).

The spelling of 6991560 in words is "six million, nine hundred ninety-one thousand, five hundred sixty".