16624981 has 8 divisors (see below), whose sum is σ = 17873280. Its totient is φ = 15414048.

The previous prime is 16624939. The next prime is 16624999. The reversal of 16624981 is 18942661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16624981 - 2¹¹ = 16622933 is a prime.

It is a super-2 number, since 2×16624981² = 552779986500722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16624981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16624081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8416 + ... + 10201.

It is an arithmetic number, because the mean of its divisors is an integer number (2234160).

Almost surely, 2^16624981 is an apocalyptic number.

It is an amenable number.

16624981 is a deficient number, since it is larger than the sum of its proper divisors (1248299).

16624981 is a wasteful number, since it uses less digits than its factorization.

16624981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18683.

The product of its digits is 20736, while the sum is 37.

The square root of 16624981 is about 4077.3742776449. The cubic root of 16624981 is about 255.2233388721.

The spelling of 16624981 in words is "sixteen million, six hundred twenty-four thousand, nine hundred eighty-one".