81980023 has 4 divisors (see below), whose sum is σ = 82024920. Its totient is φ = 81935128.

The previous prime is 81980011. The next prime is 81980047. The reversal of 81980023 is 32008918.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32008918 = 2 ⋅16004459.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81980023 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81980623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19588 + ... + 23401.

It is an arithmetic number, because the mean of its divisors is an integer number (20506230).

Almost surely, 2^81980023 is an apocalyptic number.

81980023 is a deficient number, since it is larger than the sum of its proper divisors (44897).

81980023 is a wasteful number, since it uses less digits than its factorization.

81980023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44896.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 81980023 is about 9054.2820256495. The cubic root of 81980023 is about 434.4128653429.

The spelling of 81980023 in words is "eighty-one million, nine hundred eighty thousand, twenty-three".