81374538 has 16 divisors (see below), whose sum is σ = 185999040. Its totient is φ = 23249856.

The previous prime is 81374537. The next prime is 81374539. The reversal of 81374538 is 83547318.

It is an interprime number because it is at equal distance from previous prime (81374537) and next prime (81374539).

It is a junction number, because it is equal to n+sod(n) for n = 81374496 and 81374505.

It is not an unprimeable number, because it can be changed into a prime (81374537) 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, 968703 + ... + 968786.

It is an arithmetic number, because the mean of its divisors is an integer number (11624940).

Almost surely, 2^81374538 is an apocalyptic number.

81374538 is an abundant number, since it is smaller than the sum of its proper divisors (104624502).

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

81374538 is a wasteful number, since it uses less digits than its factorization.

81374538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1937501.

The product of its digits is 80640, while the sum is 39.

The square root of 81374538 is about 9020.7836688394. The cubic root of 81374538 is about 433.3407313661.

The spelling of 81374538 in words is "eighty-one million, three hundred seventy-four thousand, five hundred thirty-eight".