11721690 has 24 divisors (see below), whose sum is σ = 30476628. Its totient is φ = 3125760.

The previous prime is 11721679. The next prime is 11721691. The reversal of 11721690 is 9612711.

It can be written as a sum of positive squares in 2 ways, for example, as 11716929 + 4761 = 3423^2 + 69^2 .

It is a super-2 number, since 2×11721690² = 274796032912200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11721691) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 65031 + ... + 65210.

Almost surely, 2^11721690 is an apocalyptic number.

11721690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

11721690 is an abundant number, since it is smaller than the sum of its proper divisors (18754938).

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

11721690 is a wasteful number, since it uses less digits than its factorization.

11721690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130254 (or 130251 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 27.

The square root of 11721690 is about 3423.6953719629. The cubic root of 11721690 is about 227.1590674830.

The spelling of 11721690 in words is "eleven million, seven hundred twenty-one thousand, six hundred ninety".