20984131 has 16 divisors (see below), whose sum is σ = 24655104. Its totient is φ = 17488224.

The previous prime is 20984123. The next prime is 20984141. The reversal of 20984131 is 13148902.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20984131 - 2³ = 20984123 is a prime.

It is a super-2 number, since 2×20984131² = 880667507650322, 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 20984131.

It is not an unprimeable number, because it can be changed into a prime (20984141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60300 + ... + 60646.

It is an arithmetic number, because the mean of its divisors is an integer number (1540944).

Almost surely, 2^20984131 is an apocalyptic number.

20984131 is a deficient number, since it is larger than the sum of its proper divisors (3670973).

20984131 is a wasteful number, since it uses less digits than its factorization.

20984131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 20984131 is about 4580.8439178824. The cubic root of 20984131 is about 275.8229058914.

It can be divided in two parts, 20984 and 131, that added together give a triangular number (21115 = T₂₀₅).

The spelling of 20984131 in words is "twenty million, nine hundred eighty-four thousand, one hundred thirty-one".