11721420 has 36 divisors (see below), whose sum is σ = 35555520. Its totient is φ = 3125664.

The previous prime is 11721419. The next prime is 11721431. The reversal of 11721420 is 2412711.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 11721393 and 11721402.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32380 + ... + 32739.

Almost surely, 2^11721420 is an apocalyptic number.

11721420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11721420 is an abundant number, since it is smaller than the sum of its proper divisors (23834100).

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

11721420 is a wasteful number, since it uses less digits than its factorization.

11721420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65134 (or 65129 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 11721420 is about 3423.6559406576. The cubic root of 11721420 is about 227.1573233256.

The spelling of 11721420 in words is "eleven million, seven hundred twenty-one thousand, four hundred twenty".