81570804 has 96 divisors (see below), whose sum is σ = 224716800. Its totient is φ = 22550400.

The previous prime is 81570799. The next prime is 81570809. The reversal of 81570804 is 40807518.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81570799) and next prime (81570809).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81570809) 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, 540129 + ... + 540279.

It is an arithmetic number, because the mean of its divisors is an integer number (2340800).

Almost surely, 2^81570804 is an apocalyptic number.

81570804 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81570804, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112358400).

81570804 is an abundant number, since it is smaller than the sum of its proper divisors (143145996).

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

81570804 is a wasteful number, since it uses less digits than its factorization.

81570804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333 (or 331 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 81570804 is about 9031.6556621696. The cubic root of 81570804 is about 433.6888409369.

The spelling of 81570804 in words is "eighty-one million, five hundred seventy thousand, eight hundred four".