81440270 has 16 divisors (see below), whose sum is σ = 154308240. Its totient is φ = 30861504.

The previous prime is 81440173. The next prime is 81440273. The reversal of 81440270 is 7204418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81440273) 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, 214127 + ... + 214506.

It is an arithmetic number, because the mean of its divisors is an integer number (9644265).

Almost surely, 2^81440270 is an apocalyptic number.

81440270 is a deficient number, since it is larger than the sum of its proper divisors (72867970).

81440270 is a wasteful number, since it uses less digits than its factorization.

81440270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428659.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 81440270 is about 9024.4262975549. The cubic root of 81440270 is about 433.4573800029.

Adding to 81440270 its reverse (7204418), we get a palindrome (88644688).

The spelling of 81440270 in words is "eighty-one million, four hundred forty thousand, two hundred seventy".