120777561 has 24 divisors (see below), whose sum is σ = 181437984. Its totient is φ = 80287200.

The previous prime is 120777557. The next prime is 120777563. The reversal of 120777561 is 165777021.

120777561 is a `hidden beast` number, since 1 + 20 + 7 + 77 + 561 = 666.

It is not a de Polignac number, because 120777561 - 2² = 120777557 is a prime.

It is a super-2 number, since 2×120777561² = 29174438482217442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (120777563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 145630 + ... + 146456.

It is an arithmetic number, because the mean of its divisors is an integer number (7559916).

Almost surely, 2^120777561 is an apocalyptic number.

It is an amenable number.

120777561 is a deficient number, since it is larger than the sum of its proper divisors (60660423).

120777561 is an frugal number, since it uses more digits than its factorization.

120777561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1443 (or 1431 counting only the distinct ones).

The product of its (nonzero) digits is 20580, while the sum is 36.

The square root of 120777561 is about 10989.8844852892. The cubic root of 120777561 is about 494.3054722543.

The spelling of 120777561 in words is "one hundred twenty million, seven hundred seventy-seven thousand, five hundred sixty-one".