81151400 has 48 divisors (see below), whose sum is σ = 205835040. Its totient is φ = 29508800.

The previous prime is 81151361. The next prime is 81151403. The reversal of 81151400 is 415118.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (81151403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16244 + ... + 20643.

It is an arithmetic number, because the mean of its divisors is an integer number (4288230).

Almost surely, 2^81151400 is an apocalyptic number.

It is an amenable number.

81151400 is an abundant number, since it is smaller than the sum of its proper divisors (124683640).

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

81151400 is a wasteful number, since it uses less digits than its factorization.

81151400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36914 (or 36905 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 20.

The square root of 81151400 is about 9008.4071844028. The cubic root of 81151400 is about 432.9442793391.

Adding to 81151400 its reverse (415118), we get a palindrome (81566518).

The spelling of 81151400 in words is "eighty-one million, one hundred fifty-one thousand, four hundred".