52393981 has 4 divisors (see below), whose sum is σ = 54200700. Its totient is φ = 50587264.

The previous prime is 52393973. The next prime is 52393987. The reversal of 52393981 is 18939325.

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 11868025 + 40525956 = 3445^2 + 6366^2 .

It is a cyclic number.

It is not a de Polignac number, because 52393981 - 2³ = 52393973 is a prime.

It is a super-2 number, since 2×52393981² = 5490258490056722, 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 (52393987) 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, 903316 + ... + 903373.

It is an arithmetic number, because the mean of its divisors is an integer number (13550175).

Almost surely, 2^52393981 is an apocalyptic number.

It is an amenable number.

52393981 is a deficient number, since it is larger than the sum of its proper divisors (1806719).

52393981 is a wasteful number, since it uses less digits than its factorization.

52393981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1806718.

The product of its digits is 58320, while the sum is 40.

The square root of 52393981 is about 7238.3686698040. The cubic root of 52393981 is about 374.1913978348.

Subtracting from 52393981 its reverse (18939325), we obtain a square (33454656 = 5784²).

The spelling of 52393981 in words is "fifty-two million, three hundred ninety-three thousand, nine hundred eighty-one".