81303537 has 32 divisors (see below), whose sum is σ = 133684992. Its totient is φ = 42891264.

The previous prime is 81303529. The next prime is 81303539. The reversal of 81303537 is 73530318.

It is not a de Polignac number, because 81303537 - 2³ = 81303529 is a prime.

It is a super-2 number, since 2×81303537² = 13220530257420738, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81303539) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16773 + ... + 21069.

It is an arithmetic number, because the mean of its divisors is an integer number (4177656).

Almost surely, 2^81303537 is an apocalyptic number.

It is an amenable number.

81303537 is a deficient number, since it is larger than the sum of its proper divisors (52381455).

81303537 is a wasteful number, since it uses less digits than its factorization.

81303537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4377.

The product of its (nonzero) digits is 7560, while the sum is 30.

The square root of 81303537 is about 9016.8473980655. The cubic root of 81303537 is about 433.2146617182.

The spelling of 81303537 in words is "eighty-one million, three hundred three thousand, five hundred thirty-seven".