20777204449 has 27 divisors (see below), whose sum is σ = 22601635641. Its totient is φ = 19096064640.

The previous prime is 20777204429. The next prime is 20777204473. The reversal of 20777204449 is 94440277702.

The square root of 20777204449 is 144143.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 1917126225 + 18860078224 = 43785^2 + 137332^2 .

It is not a de Polignac number, because 20777204449 - 2²⁵ = 20743650017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20777204399 and 20777204408.

It is not an unprimeable number, because it can be changed into a prime (20777204419) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 149476222 + ... + 149476360.

Almost surely, 2^20777204449 is an apocalyptic number.

20777204449 is the 144143-rd square number.

20777204449 is the 72072-nd centered octagonal number.

It is an amenable number.

20777204449 is a deficient number, since it is larger than the sum of its proper divisors (1824431192).

20777204449 is an frugal number, since it uses more digits than its factorization.

20777204449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434 (or 217 counting only the distinct ones).

The product of its (nonzero) digits is 790272, while the sum is 46.

The spelling of 20777204449 in words is "twenty billion, seven hundred seventy-seven million, two hundred four thousand, four hundred forty-nine".