81391962 has 16 divisors (see below), whose sum is σ = 164845440. Its totient is φ = 26787072.

The previous prime is 81391949. The next prime is 81391967. The reversal of 81391962 is 26919318.

It is a self number, because there is not a number n which added to its sum of digits gives 81391962.

It is not an unprimeable number, because it can be changed into a prime (81391967) 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, 85383 + ... + 86330.

It is an arithmetic number, because the mean of its divisors is an integer number (10302840).

Almost surely, 2^81391962 is an apocalyptic number.

81391962 is an abundant number, since it is smaller than the sum of its proper divisors (83453478).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81391962 is a wasteful number, since it uses less digits than its factorization.

81391962 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171797.

The product of its digits is 23328, while the sum is 39.

The square root of 81391962 is about 9021.7493868983. The cubic root of 81391962 is about 433.3716582803.

It can be divided in two parts, 8139 and 1962, that added together give a palindrome (10101).

The spelling of 81391962 in words is "eighty-one million, three hundred ninety-one thousand, nine hundred sixty-two".