20977505 has 4 divisors (see below), whose sum is σ = 25173012. Its totient is φ = 16782000.

The previous prime is 20977477. The next prime is 20977519. The reversal of 20977505 is 50577902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50577902 = 2 ⋅25288951.

It can be written as a sum of positive squares in 2 ways, for example, as 10679824 + 10297681 = 3268^2 + 3209^2 .

It is not a de Polignac number, because 20977505 - 2⁶ = 20977441 is a prime.

It is a Duffinian number.

It is a zygodrome in base 13.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2097746 + ... + 2097755.

It is an arithmetic number, because the mean of its divisors is an integer number (6293253).

Almost surely, 2^20977505 is an apocalyptic number.

It is an amenable number.

20977505 is a deficient number, since it is larger than the sum of its proper divisors (4195507).

20977505 is an equidigital number, since it uses as much as digits as its factorization.

20977505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4195506.

The product of its (nonzero) digits is 22050, while the sum is 35.

The square root of 20977505 is about 4580.1206315991. The cubic root of 20977505 is about 275.7938713324.

The spelling of 20977505 in words is "twenty million, nine hundred seventy-seven thousand, five hundred five".