81969783 has 16 divisors (see below), whose sum is σ = 127954176. Its totient is φ = 45696960.

The previous prime is 81969707. The next prime is 81969793. The reversal of 81969783 is 38796918.

It is not a de Polignac number, because 81969783 - 2⁸ = 81969527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81969793) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46741 + ... + 48462.

It is an arithmetic number, because the mean of its divisors is an integer number (7997136).

Almost surely, 2^81969783 is an apocalyptic number.

81969783 is a deficient number, since it is larger than the sum of its proper divisors (45984393).

81969783 is a wasteful number, since it uses less digits than its factorization.

81969783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95254.

The product of its digits is 653184, while the sum is 51.

The square root of 81969783 is about 9053.7165296910. The cubic root of 81969783 is about 434.3947773063.

The spelling of 81969783 in words is "eighty-one million, nine hundred sixty-nine thousand, seven hundred eighty-three".