81037040 has 40 divisors (see below), whose sum is σ = 215328480. Its totient is φ = 27783936.

The previous prime is 81036997. The next prime is 81037091. The reversal of 81037040 is 4073018.

It is a happy number.

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

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 81036997 and 81037015.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71795 + ... + 72914.

It is an arithmetic number, because the mean of its divisors is an integer number (5383212).

Almost surely, 2^81037040 is an apocalyptic number.

81037040 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81037040 is an abundant number, since it is smaller than the sum of its proper divisors (134291440).

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

81037040 is a wasteful number, since it uses less digits than its factorization.

81037040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144729 (or 144723 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 81037040 is about 9002.0575425844. The cubic root of 81037040 is about 432.7408128000.

The spelling of 81037040 in words is "eighty-one million, thirty-seven thousand, forty".