20439551 has 8 divisors (see below), whose sum is σ = 22612608. Its totient is φ = 18319000.

The previous prime is 20439541. The next prime is 20439557. The reversal of 20439551 is 15593402.

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 20439551 - 2⁶ = 20439487 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 (20439557) 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, 12305 + ... + 13866.

It is an arithmetic number, because the mean of its divisors is an integer number (2826576).

Almost surely, 2^20439551 is an apocalyptic number.

20439551 is a deficient number, since it is larger than the sum of its proper divisors (2173057).

20439551 is a wasteful number, since it uses less digits than its factorization.

20439551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26253.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 20439551 is about 4521.0121654338. The cubic root of 20439551 is about 273.4159108353.

The spelling of 20439551 in words is "twenty million, four hundred thirty-nine thousand, five hundred fifty-one".