77561055 has 96 divisors (see below), whose sum is σ = 167469120. Its totient is φ = 32624640.

The previous prime is 77561047. The next prime is 77561063. The reversal of 77561055 is 55016577.

It is an interprime number because it is at equal distance from previous prime (77561047) and next prime (77561063).

It is not a de Polignac number, because 77561055 - 2³ = 77561047 is a prime.

It is a congruent number.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 109041 + ... + 109749.

It is an arithmetic number, because the mean of its divisors is an integer number (1744470).

Almost surely, 2^77561055 is an apocalyptic number.

77561055 is an abundant number, since it is smaller than the sum of its proper divisors (89908065).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77561055 is a wasteful number, since it uses less digits than its factorization.

77561055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761 (or 758 counting only the distinct ones).

The product of its (nonzero) digits is 36750, while the sum is 36.

The square root of 77561055 is about 8806.8754391101. The cubic root of 77561055 is about 426.4628804520.

The spelling of 77561055 in words is "seventy-seven million, five hundred sixty-one thousand, fifty-five".