81293020 has 24 divisors (see below), whose sum is σ = 179701200. Its totient is φ = 30805632.

The previous prime is 81293011. The next prime is 81293021. The reversal of 81293020 is 2039218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81293021) 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, 106585 + ... + 107344.

It is an arithmetic number, because the mean of its divisors is an integer number (7487550).

Almost surely, 2^81293020 is an apocalyptic number.

It is an amenable number.

81293020 is an abundant number, since it is smaller than the sum of its proper divisors (98408180).

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

81293020 is a wasteful number, since it uses less digits than its factorization.

81293020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213957 (or 213955 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 81293020 is about 9016.2641931124. The cubic root of 81293020 is about 433.1959814523.

The spelling of 81293020 in words is "eighty-one million, two hundred ninety-three thousand, twenty".