81154574 has 4 divisors (see below), whose sum is σ = 121731864. Its totient is φ = 40577286.

The previous prime is 81154573. The next prime is 81154589. The reversal of 81154574 is 47545118.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 47545118 = 2 ⋅23772559.

It is a super-2 number, since 2×81154574² = 13172129762242952, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81154573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20288642 + ... + 20288645.

It is an arithmetic number, because the mean of its divisors is an integer number (30432966).

Almost surely, 2^81154574 is an apocalyptic number.

81154574 is a deficient number, since it is larger than the sum of its proper divisors (40577290).

81154574 is a wasteful number, since it uses less digits than its factorization.

81154574 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40577289.

The product of its digits is 22400, while the sum is 35.

The square root of 81154574 is about 9008.5833514488. The cubic root of 81154574 is about 432.9499237159.

The spelling of 81154574 in words is "eighty-one million, one hundred fifty-four thousand, five hundred seventy-four".