81245437 has 16 divisors (see below), whose sum is σ = 100420992. Its totient is φ = 64008000.

The previous prime is 81245429. The next prime is 81245441. The reversal of 81245437 is 73454218.

It is not a de Polignac number, because 81245437 - 2³ = 81245429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81245497) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21063 + ... + 24619.

It is an arithmetic number, because the mean of its divisors is an integer number (6276312).

Almost surely, 2^81245437 is an apocalyptic number.

It is an amenable number.

81245437 is a deficient number, since it is larger than the sum of its proper divisors (19175555).

81245437 is a wasteful number, since it uses less digits than its factorization.

81245437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3828.

The product of its digits is 26880, while the sum is 34.

The square root of 81245437 is about 9013.6250754067. The cubic root of 81245437 is about 433.1114445206. Note that the first 3 decimals are identical.

The spelling of 81245437 in words is "eighty-one million, two hundred forty-five thousand, four hundred thirty-seven".