81373980 has 96 divisors (see below), whose sum is σ = 234823680. Its totient is φ = 21047040.

The previous prime is 81373973. The next prime is 81373987. The reversal of 81373980 is 8937318.

It is an interprime number because it is at equal distance from previous prime (81373973) and next prime (81373987).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81373987) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 449490 + ... + 449670.

It is an arithmetic number, because the mean of its divisors is an integer number (2446080).

Almost surely, 2^81373980 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81373980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117411840).

81373980 is an abundant number, since it is smaller than the sum of its proper divisors (153449700).

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

81373980 is a wasteful number, since it uses less digits than its factorization.

81373980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 81373980 is about 9020.7527402097. The cubic root of 81373980 is about 433.3397408651.

The spelling of 81373980 in words is "eighty-one million, three hundred seventy-three thousand, nine hundred eighty".