20977609 has 8 divisors (see below), whose sum is σ = 22754088. Its totient is φ = 19261440.

The previous prime is 20977601. The next prime is 20977613. The reversal of 20977609 is 90677902.

It can be written as a sum of positive squares in 4 ways, for example, as 138384 + 20839225 = 372^2 + 4565^2 .

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 20977609 - 2³ = 20977601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20977601) 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, 14352 + ... + 15745.

It is an arithmetic number, because the mean of its divisors is an integer number (2844261).

Almost surely, 2^20977609 is an apocalyptic number.

It is an amenable number.

20977609 is a deficient number, since it is larger than the sum of its proper divisors (1776479).

20977609 is a wasteful number, since it uses less digits than its factorization.

20977609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30155.

The product of its (nonzero) digits is 47628, while the sum is 40.

The square root of 20977609 is about 4580.1319849978. The cubic root of 20977609 is about 275.7943270986.

The spelling of 20977609 in words is "twenty million, nine hundred seventy-seven thousand, six hundred nine".