16402981 has 4 divisors (see below), whose sum is σ = 18746272. Its totient is φ = 14059692.

The previous prime is 16402949. The next prime is 16403017. The reversal of 16402981 is 18920461.

It is a happy number.

16402981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16402981 - 2⁵ = 16402949 is a prime.

It is a super-2 number, since 2×16402981² = 538115571372722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16402931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1171635 + ... + 1171648.

It is an arithmetic number, because the mean of its divisors is an integer number (4686568).

Almost surely, 2^16402981 is an apocalyptic number.

It is an amenable number.

16402981 is a deficient number, since it is larger than the sum of its proper divisors (2343291).

16402981 is an equidigital number, since it uses as much as digits as its factorization.

16402981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2343290.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 16402981 is about 4050.0593822807. The cubic root of 16402981 is about 254.0822113858.

The spelling of 16402981 in words is "sixteen million, four hundred two thousand, nine hundred eighty-one".