81237145 has 8 divisors (see below), whose sum is σ = 106346880. Its totient is φ = 59081520.

The previous prime is 81237139. The next prime is 81237151. The reversal of 81237145 is 54173218.

It is an interprime number because it is at equal distance from previous prime (81237139) and next prime (81237151).

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

It is not a de Polignac number, because 81237145 - 2¹⁵ = 81204377 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 738465 + ... + 738574.

It is an arithmetic number, because the mean of its divisors is an integer number (13293360).

Almost surely, 2^81237145 is an apocalyptic number.

It is an amenable number.

81237145 is a deficient number, since it is larger than the sum of its proper divisors (25109735).

81237145 is a wasteful number, since it uses less digits than its factorization.

81237145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1477055.

The product of its digits is 6720, while the sum is 31.

The square root of 81237145 is about 9013.1650933509. The cubic root of 81237145 is about 433.0967094068.

The spelling of 81237145 in words is "eighty-one million, two hundred thirty-seven thousand, one hundred forty-five".