2631777561 has 20 divisors (see below), whose sum is σ = 4493053312. Its totient is φ = 1503872568.

The previous prime is 2631777557. The next prime is 2631777611. The reversal of 2631777561 is 1657771362.

2631777561 is a `hidden beast` number, since 2 + 6 + 3 + 17 + 77 + 561 = 666.

It is not a de Polignac number, because 2631777561 - 2² = 2631777557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2631776561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2320225 + ... + 2321358.

Almost surely, 2^2631777561 is an apocalyptic number.

2631777561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2631777561 is a deficient number, since it is larger than the sum of its proper divisors (1861275751).

2631777561 is an equidigital number, since it uses as much as digits as its factorization.

2631777561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4641602 (or 4641593 counting only the distinct ones).

The product of its digits is 370440, while the sum is 45.

The square root of 2631777561 is about 51300.8534139540. The cubic root of 2631777561 is about 1380.6482918083.

The spelling of 2631777561 in words is "two billion, six hundred thirty-one million, seven hundred seventy-seven thousand, five hundred sixty-one".