53776781 has 4 divisors (see below), whose sum is σ = 53809212. Its totient is φ = 53744352.

The previous prime is 53776777. The next prime is 53776787. The reversal of 53776781 is 18767735.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17355556 + 36421225 = 4166^2 + 6035^2 .

It is a cyclic number.

It is not a de Polignac number, because 53776781 - 2² = 53776777 is a prime.

It is a super-2 number, since 2×53776781² = 5783884349443922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53776787) 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, 13586 + ... + 17091.

It is an arithmetic number, because the mean of its divisors is an integer number (13452303).

Almost surely, 2^53776781 is an apocalyptic number.

It is an amenable number.

53776781 is a deficient number, since it is larger than the sum of its proper divisors (32431).

53776781 is a wasteful number, since it uses less digits than its factorization.

53776781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32430.

The product of its digits is 246960, while the sum is 44.

The square root of 53776781 is about 7333.2653708972. The cubic root of 53776781 is about 377.4547839942.

The spelling of 53776781 in words is "fifty-three million, seven hundred seventy-six thousand, seven hundred eighty-one".