81513301 has 4 divisors (see below), whose sum is σ = 82032652. Its totient is φ = 80993952.

The previous prime is 81513259. The next prime is 81513319. The reversal of 81513301 is 10331518.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6708100 + 74805201 = 2590^2 + 8649^2 .

It is a cyclic number.

It is not a de Polignac number, because 81513301 - 2²³ = 73124693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81013301) 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, 259440 + ... + 259753.

It is an arithmetic number, because the mean of its divisors is an integer number (20508163).

Almost surely, 2^81513301 is an apocalyptic number.

It is an amenable number.

81513301 is a deficient number, since it is larger than the sum of its proper divisors (519351).

81513301 is a wasteful number, since it uses less digits than its factorization.

81513301 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519350.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 81513301 is about 9028.4716868360. The cubic root of 81513301 is about 433.5869079308.

Adding to 81513301 its reverse (10331518), we get a palindrome (91844819).

The spelling of 81513301 in words is "eighty-one million, five hundred thirteen thousand, three hundred one".