81490451 has 8 divisors (see below), whose sum is σ = 94003200. Its totient is φ = 69195528.

The previous prime is 81490427. The next prime is 81490481. The reversal of 81490451 is 15409418.

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 81490451 - 2¹⁴ = 81474067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81490421) 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, 53651 + ... + 55148.

It is an arithmetic number, because the mean of its divisors is an integer number (11750400).

Almost surely, 2^81490451 is an apocalyptic number.

81490451 is a deficient number, since it is larger than the sum of its proper divisors (12512749).

81490451 is a wasteful number, since it uses less digits than its factorization.

81490451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108913.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 81490451 is about 9027.2061569458. The cubic root of 81490451 is about 433.5463894443.

Adding to 81490451 its reverse (15409418), we get a palindrome (96899869).

The spelling of 81490451 in words is "eighty-one million, four hundred ninety thousand, four hundred fifty-one".