81935451 has 12 divisors (see below), whose sum is σ = 127455328. Its totient is φ = 50421744.

The previous prime is 81935443. The next prime is 81935471. The reversal of 81935451 is 15453918.

It is not a de Polignac number, because 81935451 - 2³ = 81935443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81935401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 350035 + ... + 350268.

Almost surely, 2^81935451 is an apocalyptic number.

81935451 is a deficient number, since it is larger than the sum of its proper divisors (45519877).

81935451 is a wasteful number, since it uses less digits than its factorization.

81935451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700322 (or 700319 counting only the distinct ones).

The product of its digits is 21600, while the sum is 36.

The square root of 81935451 is about 9051.8203141689. The cubic root of 81935451 is about 434.3341219300.

The spelling of 81935451 in words is "eighty-one million, nine hundred thirty-five thousand, four hundred fifty-one".