81964290 has 32 divisors (see below), whose sum is σ = 207069120. Its totient is φ = 20706624.

The previous prime is 81964261. The next prime is 81964291. The reversal of 81964290 is 9246918.

It is not an unprimeable number, because it can be changed into a prime (81964291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71329 + ... + 72468.

It is an arithmetic number, because the mean of its divisors is an integer number (6470910).

Almost surely, 2^81964290 is an apocalyptic number.

81964290 is an abundant number, since it is smaller than the sum of its proper divisors (125104830).

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

81964290 is a wasteful number, since it uses less digits than its factorization.

81964290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143826.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 81964290 is about 9053.4131685238. The cubic root of 81964290 is about 434.3850737964.

The spelling of 81964290 in words is "eighty-one million, nine hundred sixty-four thousand, two hundred ninety".