51977566 has 4 divisors (see below), whose sum is σ = 77966352. Its totient is φ = 25988782.

The previous prime is 51977561. The next prime is 51977591. The reversal of 51977566 is 66577915.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66577915 = 5 ⋅13315583.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51977561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12994390 + ... + 12994393.

It is an arithmetic number, because the mean of its divisors is an integer number (19491588).

Almost surely, 2^51977566 is an apocalyptic number.

51977566 is a deficient number, since it is larger than the sum of its proper divisors (25988786).

51977566 is a wasteful number, since it uses less digits than its factorization.

51977566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25988785.

The product of its digits is 396900, while the sum is 46.

The square root of 51977566 is about 7209.5468650949. The cubic root of 51977566 is about 373.1974315792.

It can be divided in two parts, 519775 and 66, that added together give a square (519841 = 721²).

The spelling of 51977566 in words is "fifty-one million, nine hundred seventy-seven thousand, five hundred sixty-six".