81421310 has 8 divisors (see below), whose sum is σ = 146558376. Its totient is φ = 32568520.

The previous prime is 81421297. The next prime is 81421339. The reversal of 81421310 is 1312418.

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

It is a super-2 number, since 2×81421310² = 13258859444232200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4071056 + ... + 4071075.

It is an arithmetic number, because the mean of its divisors is an integer number (18319797).

Almost surely, 2^81421310 is an apocalyptic number.

81421310 is a deficient number, since it is larger than the sum of its proper divisors (65137066).

81421310 is a wasteful number, since it uses less digits than its factorization.

81421310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8142138.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 81421310 is about 9023.3757541177. The cubic root of 81421310 is about 433.4237398485.

Adding to 81421310 its reverse (1312418), we get a palindrome (82733728).

The spelling of 81421310 in words is "eighty-one million, four hundred twenty-one thousand, three hundred ten".