81401507 has 4 divisors (see below), whose sum is σ = 88801656. Its totient is φ = 74001360.

The previous prime is 81401501. The next prime is 81401513. The reversal of 81401507 is 70510418.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (81401501) and next prime (81401513).

It is a cyclic number.

It is not a de Polignac number, because 81401507 - 2⁸ = 81401251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81401501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3700058 + ... + 3700079.

It is an arithmetic number, because the mean of its divisors is an integer number (22200414).

Almost surely, 2^81401507 is an apocalyptic number.

81401507 is a deficient number, since it is larger than the sum of its proper divisors (7400149).

81401507 is a wasteful number, since it uses less digits than its factorization.

81401507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7400148.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 81401507 is about 9022.2783707886. The cubic root of 81401507 is about 433.3885984084.

The spelling of 81401507 in words is "eighty-one million, four hundred one thousand, five hundred seven".