81001792 has 14 divisors (see below), whose sum is σ = 160738058. Its totient is φ = 40500864.

The previous prime is 81001777. The next prime is 81001793. The reversal of 81001792 is 29710018.

It can be written as a sum of positive squares in only one way, i.e., 40755456 + 40246336 = 6384^2 + 6344^2 .

It is a super-2 number, since 2×81001792² = 13122580614422528, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81001792.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81001793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632763 + ... + 632890.

Almost surely, 2^81001792 is an apocalyptic number.

It is an amenable number.

81001792 is a deficient number, since it is larger than the sum of its proper divisors (79736266).

81001792 is a wasteful number, since it uses less digits than its factorization.

81001792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1265665 (or 1265655 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 81001792 is about 9000.0995550049. The cubic root of 81001792 is about 432.6780618233.

The spelling of 81001792 in words is "eighty-one million, one thousand, seven hundred ninety-two".