20988407 has 16 divisors (see below), whose sum is σ = 24261120. Its totient is φ = 17956800.

The previous prime is 20988403. The next prime is 20988437. The reversal of 20988407 is 70488902.

It is a cyclic number.

It is not a de Polignac number, because 20988407 - 2² = 20988403 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20988403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48482 + ... + 48912.

It is an arithmetic number, because the mean of its divisors is an integer number (1516320).

Almost surely, 2^20988407 is an apocalyptic number.

20988407 is a deficient number, since it is larger than the sum of its proper divisors (3272713).

20988407 is a wasteful number, since it uses less digits than its factorization.

20988407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694.

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 20988407 is about 4581.3106203356. The cubic root of 20988407 is about 275.8416397089.

The spelling of 20988407 in words is "twenty million, nine hundred eighty-eight thousand, four hundred seven".