81963739 has 32 divisors (see below), whose sum is σ = 102735360. Its totient is φ = 64281600.

The previous prime is 81963727. The next prime is 81963751. The reversal of 81963739 is 93736918.

It is an interprime number because it is at equal distance from previous prime (81963727) and next prime (81963751).

It is a cyclic number.

It is not a de Polignac number, because 81963739 - 2⁷ = 81963611 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81963709) 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, 263394 + ... + 263704.

It is an arithmetic number, because the mean of its divisors is an integer number (3210480).

Almost surely, 2^81963739 is an apocalyptic number.

81963739 is a deficient number, since it is larger than the sum of its proper divisors (20771621).

81963739 is a wasteful number, since it uses less digits than its factorization.

81963739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451.

The product of its digits is 244944, while the sum is 46.

The square root of 81963739 is about 9053.3827379604. The cubic root of 81963739 is about 434.3841004183.

It can be divided in two parts, 8196 and 3739, that added together give a triangular number (11935 = T₁₅₄).

The spelling of 81963739 in words is "eighty-one million, nine hundred sixty-three thousand, seven hundred thirty-nine".