81502401 has 8 divisors (see below), whose sum is σ = 109390144. Its totient is φ = 53974800.

The previous prime is 81502387. The next prime is 81502417. The reversal of 81502401 is 10420518.

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

It is not a de Polignac number, because 81502401 - 2⁷ = 81502273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81501401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89506 + ... + 90411.

It is an arithmetic number, because the mean of its divisors is an integer number (13673768).

Almost surely, 2^81502401 is an apocalyptic number.

It is an amenable number.

81502401 is a deficient number, since it is larger than the sum of its proper divisors (27887743).

81502401 is a wasteful number, since it uses less digits than its factorization.

81502401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180071.

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 81502401 is about 9027.8680207455. The cubic root of 81502401 is about 433.5675805821.

Adding to 81502401 its reverse (10420518), we get a palindrome (91922919).

The spelling of 81502401 in words is "eighty-one million, five hundred two thousand, four hundred one".