81563374 has 8 divisors (see below), whose sum is σ = 122421240. Its totient is φ = 40756296.

The previous prime is 81563329. The next prime is 81563381. The reversal of 81563374 is 47336518.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8389 + ... + 15280.

It is an arithmetic number, because the mean of its divisors is an integer number (15302655).

Almost surely, 2^81563374 is an apocalyptic number.

81563374 is a deficient number, since it is larger than the sum of its proper divisors (40857866).

81563374 is a wasteful number, since it uses less digits than its factorization.

81563374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25394.

The product of its digits is 60480, while the sum is 37.

The square root of 81563374 is about 9031.2443217975. The cubic root of 81563374 is about 433.6756728025.

The spelling of 81563374 in words is "eighty-one million, five hundred sixty-three thousand, three hundred seventy-four".