81351774 has 24 divisors (see below), whose sum is σ = 201442800. Its totient is φ = 23243328.

The previous prime is 81351773. The next prime is 81351791. The reversal of 81351774 is 47715318.

It is a super-2 number, since 2×81351774² = 13236222265894152, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81351773) 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, 322699 + ... + 322950.

It is an arithmetic number, because the mean of its divisors is an integer number (8393450).

Almost surely, 2^81351774 is an apocalyptic number.

81351774 is an abundant number, since it is smaller than the sum of its proper divisors (120091026).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81351774 is a wasteful number, since it uses less digits than its factorization.

81351774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645664 (or 645661 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 81351774 is about 9019.5218276802. The cubic root of 81351774 is about 433.3003195099.

The spelling of 81351774 in words is "eighty-one million, three hundred fifty-one thousand, seven hundred seventy-four".