81272155 has 8 divisors (see below), whose sum is σ = 103263552. Its totient is φ = 61193088.

The previous prime is 81272131. The next prime is 81272159. The reversal of 81272155 is 55127218.

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 81272155 - 2⁹ = 81271643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81272159) 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, 477987 + ... + 478156.

It is an arithmetic number, because the mean of its divisors is an integer number (12907944).

Almost surely, 2^81272155 is an apocalyptic number.

81272155 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81272155 is a deficient number, since it is larger than the sum of its proper divisors (21991397).

81272155 is a wasteful number, since it uses less digits than its factorization.

81272155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956165.

The product of its digits is 5600, while the sum is 31.

The square root of 81272155 is about 9015.1070431804. The cubic root of 81272155 is about 433.1589163285.

The spelling of 81272155 in words is "eighty-one million, two hundred seventy-two thousand, one hundred fifty-five".