81542379 has 8 divisors (see below), whose sum is σ = 108802512. Its totient is φ = 54321920.

The previous prime is 81542359. The next prime is 81542381. The reversal of 81542379 is 97324518.

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

It is a cyclic number.

It is not a de Polignac number, because 81542379 - 2⁵ = 81542347 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81542359) 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, 4734 + ... + 13619.

It is an arithmetic number, because the mean of its divisors is an integer number (13600314).

Almost surely, 2^81542379 is an apocalyptic number.

81542379 is a deficient number, since it is larger than the sum of its proper divisors (27260133).

81542379 is a wasteful number, since it uses less digits than its factorization.

81542379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19837.

The product of its digits is 60480, while the sum is 39.

The square root of 81542379 is about 9030.0818933164. The cubic root of 81542379 is about 433.6384591953.

The spelling of 81542379 in words is "eighty-one million, five hundred forty-two thousand, three hundred seventy-nine".