81401506 has 8 divisors (see below), whose sum is σ = 122472144. Its totient is φ = 40577460.

The previous prime is 81401501. The next prime is 81401513. The reversal of 81401506 is 60510418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (81401501) 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, 60820 + ... + 62143.

It is an arithmetic number, because the mean of its divisors is an integer number (15309018).

Almost surely, 2^81401506 is an apocalyptic number.

81401506 is a deficient number, since it is larger than the sum of its proper divisors (41070638).

81401506 is a wasteful number, since it uses less digits than its factorization.

81401506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123296.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 81401506 is about 9022.2783153702. The cubic root of 81401506 is about 433.3885966337.

The spelling of 81401506 in words is "eighty-one million, four hundred one thousand, five hundred six".