61888381 has 4 divisors (see below), whose sum is σ = 65528892. Its totient is φ = 58247872.

The previous prime is 61888367. The next prime is 61888399. The reversal of 61888381 is 18388816.

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 57244356 + 4644025 = 7566^2 + 2155^2 .

It is a cyclic number.

It is not a de Polignac number, because 61888381 - 2⁹ = 61887869 is a prime.

It is a super-2 number, since 2×61888381² = 7660343405602322, 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 (61888361) 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, 1820230 + ... + 1820263.

It is an arithmetic number, because the mean of its divisors is an integer number (16382223).

Almost surely, 2^61888381 is an apocalyptic number.

It is an amenable number.

61888381 is a deficient number, since it is larger than the sum of its proper divisors (3640511).

61888381 is a wasteful number, since it uses less digits than its factorization.

61888381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3640510.

The product of its digits is 73728, while the sum is 43.

The square root of 61888381 is about 7866.9168674901. The cubic root of 61888381 is about 395.5515043660.

The spelling of 61888381 in words is "sixty-one million, eight hundred eighty-eight thousand, three hundred eighty-one".