81431455 has 8 divisors (see below), whose sum is σ = 111677472. Its totient is φ = 55838688.

The previous prime is 81431447. The next prime is 81431509. The reversal of 81431455 is 55413418.

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

It is a cyclic number.

It is not a de Polignac number, because 81431455 - 2³ = 81431447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1163272 + ... + 1163341.

It is an arithmetic number, because the mean of its divisors is an integer number (13959684).

Almost surely, 2^81431455 is an apocalyptic number.

81431455 is a deficient number, since it is larger than the sum of its proper divisors (30246017).

81431455 is a wasteful number, since it uses less digits than its factorization.

81431455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2326625.

The product of its digits is 9600, while the sum is 31.

The square root of 81431455 is about 9023.9378876408. The cubic root of 81431455 is about 433.4417404646.

The spelling of 81431455 in words is "eighty-one million, four hundred thirty-one thousand, four hundred fifty-five".