20989407 has 8 divisors (see below), whose sum is σ = 29632176. Its totient is φ = 13169792.

The previous prime is 20989393. The next prime is 20989421. The reversal of 20989407 is 70498902.

It is an interprime number because it is at equal distance from previous prime (20989393) and next prime (20989421).

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 20989407 - 2⁴ = 20989391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20989457) 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, 205728 + ... + 205829.

It is an arithmetic number, because the mean of its divisors is an integer number (3704022).

Almost surely, 2^20989407 is an apocalyptic number.

20989407 is a deficient number, since it is larger than the sum of its proper divisors (8642769).

20989407 is a wasteful number, since it uses less digits than its factorization.

20989407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411577.

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 20989407 is about 4581.4197581099. The cubic root of 20989407 is about 275.8460204965.

The spelling of 20989407 in words is "twenty million, nine hundred eighty-nine thousand, four hundred seven".