81513254 has 16 divisors (see below), whose sum is σ = 124540416. Its totient is φ = 40005000.

The previous prime is 81513241. The next prime is 81513259. The reversal of 81513254 is 45231518.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81513259) 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, 34499 + ... + 36785.

It is an arithmetic number, because the mean of its divisors is an integer number (7783776).

Almost surely, 2^81513254 is an apocalyptic number.

81513254 is a deficient number, since it is larger than the sum of its proper divisors (43027162).

81513254 is a wasteful number, since it uses less digits than its factorization.

81513254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2611.

The product of its digits is 4800, while the sum is 29.

The square root of 81513254 is about 9028.4690839588. The cubic root of 81513254 is about 433.5868245964.

The spelling of 81513254 in words is "eighty-one million, five hundred thirteen thousand, two hundred fifty-four".