81929460 has 96 divisors (see below), whose sum is σ = 248209920. Its totient is φ = 20113408.

The previous prime is 81929459. The next prime is 81929461. The reversal of 81929460 is 6492918.

It is an interprime number because it is at equal distance from previous prime (81929459) and next prime (81929461).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81929461) 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, 47086 + ... + 48794.

It is an arithmetic number, because the mean of its divisors is an integer number (2585520).

Almost surely, 2^81929460 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 81929460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124104960).

81929460 is an abundant number, since it is smaller than the sum of its proper divisors (166280460).

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

81929460 is a wasteful number, since it uses less digits than its factorization.

81929460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1785 (or 1783 counting only the distinct ones).

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

The square root of 81929460 is about 9051.4893802070. The cubic root of 81929460 is about 434.3235357140.

The spelling of 81929460 in words is "eighty-one million, nine hundred twenty-nine thousand, four hundred sixty".