81401390 has 16 divisors (see below), whose sum is σ = 167454432. Its totient is φ = 27909024.

The previous prime is 81401387. The next prime is 81401399. The reversal of 81401390 is 9310418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81401399) 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 7 ways as a sum of consecutive naturals, for example, 581369 + ... + 581508.

It is an arithmetic number, because the mean of its divisors is an integer number (10465902).

Almost surely, 2^81401390 is an apocalyptic number.

81401390 is an abundant number, since it is smaller than the sum of its proper divisors (86053042).

81401390 is a wasteful number, since it uses less digits than its factorization.

81401390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1162891.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 81401390 is about 9022.2718868365. The cubic root of 81401390 is about 433.3883907690.

The spelling of 81401390 in words is "eighty-one million, four hundred one thousand, three hundred ninety".