51778571 has 4 divisors (see below), whose sum is σ = 55761552. Its totient is φ = 47795592.

The previous prime is 51778567. The next prime is 51778607. The reversal of 51778571 is 17587715.

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: 17587715 = 5 ⋅3517543.

It is not a de Polignac number, because 51778571 - 2² = 51778567 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51778501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1991471 + ... + 1991496.

It is an arithmetic number, because the mean of its divisors is an integer number (13940388).

Almost surely, 2^51778571 is an apocalyptic number.

51778571 is a deficient number, since it is larger than the sum of its proper divisors (3982981).

51778571 is a wasteful number, since it uses less digits than its factorization.

51778571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3982980.

The product of its digits is 68600, while the sum is 41.

The square root of 51778571 is about 7195.7328327280. The cubic root of 51778571 is about 372.7205630379.

The spelling of 51778571 in words is "fifty-one million, seven hundred seventy-eight thousand, five hundred seventy-one".