81572151 has 8 divisors (see below), whose sum is σ = 110073600. Its totient is φ = 53726072.

The previous prime is 81572147. The next prime is 81572167. The reversal of 81572151 is 15127518.

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 81572151 - 2² = 81572147 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81572131) 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, 163551 + ... + 164048.

It is an arithmetic number, because the mean of its divisors is an integer number (13759200).

Almost surely, 2^81572151 is an apocalyptic number.

81572151 is a deficient number, since it is larger than the sum of its proper divisors (28501449).

81572151 is a wasteful number, since it uses less digits than its factorization.

81572151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327685.

The product of its digits is 2800, while the sum is 30.

The square root of 81572151 is about 9031.7302329066. The cubic root of 81572151 is about 433.6912281295.

Adding to 81572151 its reverse (15127518), we get a palindrome (96699669).

The spelling of 81572151 in words is "eighty-one million, five hundred seventy-two thousand, one hundred fifty-one".