81481370 has 8 divisors (see below), whose sum is σ = 146666484. Its totient is φ = 32592544.

The previous prime is 81481339. The next prime is 81481373. The reversal of 81481370 is 7318418.

It can be written as a sum of positive squares in 2 ways, for example, as 79192201 + 2289169 = 8899^2 + 1513^2 .

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

It is not an unprimeable number, because it can be changed into a prime (81481373) 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, 4074059 + ... + 4074078.

Almost surely, 2^81481370 is an apocalyptic number.

81481370 is a deficient number, since it is larger than the sum of its proper divisors (65185114).

81481370 is a wasteful number, since it uses less digits than its factorization.

81481370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8148144.

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 81481370 is about 9026.7031633925. The cubic root of 81481370 is about 433.5302845675.

Adding to 81481370 its reverse (7318418), we get a palindrome (88799788).

The spelling of 81481370 in words is "eighty-one million, four hundred eighty-one thousand, three hundred seventy".