81907742 has 16 divisors (see below), whose sum is σ = 140743680. Its totient is φ = 35020728.

The previous prime is 81907741. The next prime is 81907747. The reversal of 81907742 is 24770918.

It is a junction number, because it is equal to n+sod(n) for n = 81907696 and 81907705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81907741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 518 + ... + 12809.

It is an arithmetic number, because the mean of its divisors is an integer number (8796480).

Almost surely, 2^81907742 is an apocalyptic number.

81907742 is a deficient number, since it is larger than the sum of its proper divisors (58835938).

81907742 is a wasteful number, since it uses less digits than its factorization.

81907742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13775.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 81907742 is about 9050.2896086258. The cubic root of 81907742 is about 434.2851552497.

The spelling of 81907742 in words is "eighty-one million, nine hundred seven thousand, seven hundred forty-two".