81772427 has 8 divisors (see below), whose sum is σ = 89888832. Its totient is φ = 73769800.

The previous prime is 81772393. The next prime is 81772463. The reversal of 81772427 is 72427718.

It is a happy number.

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 81772427 - 2¹² = 81768331 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81772477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26933 + ... + 29814.

It is an arithmetic number, because the mean of its divisors is an integer number (11236104).

Almost surely, 2^81772427 is an apocalyptic number.

81772427 is a deficient number, since it is larger than the sum of its proper divisors (8116405).

81772427 is a wasteful number, since it uses less digits than its factorization.

81772427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56889.

The product of its digits is 43904, while the sum is 38.

The square root of 81772427 is about 9042.8107908990. The cubic root of 81772427 is about 434.0458710461.

The spelling of 81772427 in words is "eighty-one million, seven hundred seventy-two thousand, four hundred twenty-seven".