53781381 has 32 divisors (see below), whose sum is σ = 85948800. Its totient is φ = 33125760.

The previous prime is 53781367. The next prime is 53781407. The reversal of 53781381 is 18318735.

It is not a de Polignac number, because 53781381 - 2⁶ = 53781317 is a prime.

It is a super-2 number, since 2×53781381² = 5784873884534322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53781781) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19755 + ... + 22311.

It is an arithmetic number, because the mean of its divisors is an integer number (2685900).

Almost surely, 2^53781381 is an apocalyptic number.

It is an amenable number.

53781381 is a deficient number, since it is larger than the sum of its proper divisors (32167419).

53781381 is a wasteful number, since it uses less digits than its factorization.

53781381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2626 (or 2620 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 53781381 is about 7333.5790034607. The cubic root of 53781381 is about 377.4655460273.

It can be divided in two parts, 537 and 81381, that added together give a palindrome (81918).

The spelling of 53781381 in words is "fifty-three million, seven hundred eighty-one thousand, three hundred eighty-one".