51777566 has 4 divisors (see below), whose sum is σ = 77666352. Its totient is φ = 25888782.

The previous prime is 51777553. The next prime is 51777569. The reversal of 51777566 is 66577715.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66577715 = 5 ⋅13315543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51777569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12944390 + ... + 12944393.

It is an arithmetic number, because the mean of its divisors is an integer number (19416588).

Almost surely, 2^51777566 is an apocalyptic number.

51777566 is a deficient number, since it is larger than the sum of its proper divisors (25888786).

51777566 is a wasteful number, since it uses less digits than its factorization.

51777566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25888785.

The product of its digits is 308700, while the sum is 44.

The square root of 51777566 is about 7195.6629993351. The cubic root of 51777566 is about 372.7181515732.

The spelling of 51777566 in words is "fifty-one million, seven hundred seventy-seven thousand, five hundred sixty-six".