61681239 has 24 divisors (see below), whose sum is σ = 97868160. Its totient is φ = 37260432.

The previous prime is 61681237. The next prime is 61681267. The reversal of 61681239 is 93218616.

61681239 is a `hidden beast` number, since 616 + 8 + 1 + 2 + 39 = 666.

It is not a de Polignac number, because 61681239 - 2¹ = 61681237 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61681237) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3909 + ... + 11774.

It is an arithmetic number, because the mean of its divisors is an integer number (4077840).

Almost surely, 2^61681239 is an apocalyptic number.

61681239 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

61681239 is a deficient number, since it is larger than the sum of its proper divisors (36186921).

61681239 is a wasteful number, since it uses less digits than its factorization.

61681239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15731 (or 15728 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 61681239 is about 7853.7404464370. The cubic root of 61681239 is about 395.1097040799.

The spelling of 61681239 in words is "sixty-one million, six hundred eighty-one thousand, two hundred thirty-nine".