81790160 has 20 divisors (see below), whose sum is σ = 190162308. Its totient is φ = 32716032.

The previous prime is 81790153. The next prime is 81790169. The reversal of 81790160 is 6109718.

It can be written as a sum of positive squares in 2 ways, for example, as 64384576 + 17405584 = 8024^2 + 4172^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81790169) 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, 511109 + ... + 511268.

Almost surely, 2^81790160 is an apocalyptic number.

81790160 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81790160 is an abundant number, since it is smaller than the sum of its proper divisors (108372148).

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

81790160 is a wasteful number, since it uses less digits than its factorization.

81790160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1022390 (or 1022384 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 81790160 is about 9043.7912404036. The cubic root of 81790160 is about 434.0772442094.

Adding to 81790160 its reverse (6109718), we get a palindrome (87899878).

The spelling of 81790160 in words is "eighty-one million, seven hundred ninety thousand, one hundred sixty".