81964598 has 4 divisors (see below), whose sum is σ = 122946900. Its totient is φ = 40982298.

The previous prime is 81964567. The next prime is 81964607. The reversal of 81964598 is 89546918.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 89546918 = 2 ⋅44773459.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20491148 + ... + 20491151.

It is an arithmetic number, because the mean of its divisors is an integer number (30736725).

Almost surely, 2^81964598 is an apocalyptic number.

81964598 is a deficient number, since it is larger than the sum of its proper divisors (40982302).

81964598 is a wasteful number, since it uses less digits than its factorization.

81964598 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40982301.

The product of its digits is 622080, while the sum is 50.

The square root of 81964598 is about 9053.4301786671. The cubic root of 81964598 is about 434.3856178969.

The spelling of 81964598 in words is "eighty-one million, nine hundred sixty-four thousand, five hundred ninety-eight".