81437387 has 8 divisors (see below), whose sum is σ = 82659840. Its totient is φ = 80219880.

The previous prime is 81437381. The next prime is 81437393. The reversal of 81437387 is 78373418.

It is an interprime number because it is at equal distance from previous prime (81437381) and next prime (81437393).

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 81437387 - 2⁴ = 81437371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81437381) 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, 43562 + ... + 45392.

It is an arithmetic number, because the mean of its divisors is an integer number (10332480).

Almost surely, 2^81437387 is an apocalyptic number.

81437387 is a deficient number, since it is larger than the sum of its proper divisors (1222453).

81437387 is a wasteful number, since it uses less digits than its factorization.

81437387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2473.

The product of its digits is 112896, while the sum is 41.

The square root of 81437387 is about 9024.2665629956. The cubic root of 81437387 is about 433.4522651199.

The spelling of 81437387 in words is "eighty-one million, four hundred thirty-seven thousand, three hundred eighty-seven".