81145000 has 40 divisors (see below), whose sum is σ = 190134450. Its totient is φ = 32456000.

The previous prime is 81144997. The next prime is 81145039. The reversal of 81145000 is 54118.

It can be written as a sum of positive squares in 5 ways, for example, as 13675204 + 67469796 = 3698^2 + 8214^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×81145000² = 13169022050000000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3115 + ... + 13114.

Almost surely, 2^81145000 is an apocalyptic number.

It is an amenable number.

81145000 is an abundant number, since it is smaller than the sum of its proper divisors (108989450).

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

81145000 is a wasteful number, since it uses less digits than its factorization.

81145000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16255 (or 16236 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 81145000 is about 9008.0519536690. The cubic root of 81145000 is about 432.9328976656.

Adding to 81145000 its reverse (54118), we get a palindrome (81199118).

The spelling of 81145000 in words is "eighty-one million, one hundred forty-five thousand".