81407503 has 2 divisors, whose sum is σ = 81407504. Its totient is φ = 81407502.

The previous prime is 81407477. The next prime is 81407527. The reversal of 81407503 is 30570418.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81407503 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81407563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40703751 + 40703752.

It is an arithmetic number, because the mean of its divisors is an integer number (40703752).

Almost surely, 2^81407503 is an apocalyptic number.

81407503 is a deficient number, since it is larger than the sum of its proper divisors (1).

81407503 is an equidigital number, since it uses as much as digits as its factorization.

81407503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 81407503 is about 9022.6106532422. The cubic root of 81407503 is about 433.3992392198.

The spelling of 81407503 in words is "eighty-one million, four hundred seven thousand, five hundred three".