81418431 has 16 divisors (see below), whose sum is σ = 112578560. Its totient is φ = 52284960.

The previous prime is 81418409. The next prime is 81418481. The reversal of 81418431 is 13481418.

It is not a de Polignac number, because 81418431 - 2¹⁵ = 81385663 is a prime.

It is a super-2 number, since 2×81418431² = 13257921813003522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81418481) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19386 + ... + 23208.

It is an arithmetic number, because the mean of its divisors is an integer number (7036160).

Almost surely, 2^81418431 is an apocalyptic number.

81418431 is a deficient number, since it is larger than the sum of its proper divisors (31160129).

81418431 is a wasteful number, since it uses less digits than its factorization.

81418431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4086.

The product of its digits is 3072, while the sum is 30.

The square root of 81418431 is about 9023.2162226115. The cubic root of 81418431 is about 433.4186312692.

Adding to 81418431 its reverse (13481418), we get a palindrome (94899849).

The spelling of 81418431 in words is "eighty-one million, four hundred eighteen thousand, four hundred thirty-one".