81503616490 has 8 divisors (see below), whose sum is σ = 146706509700. Its totient is φ = 32601446592.

The previous prime is 81503616451. The next prime is 81503616497. The reversal of 81503616490 is 9461630518.

It can be written as a sum of positive squares in 2 ways, for example, as 73637877769 + 7865738721 = 271363^2 + 88689^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (81503616497) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4075180815 + ... + 4075180834.

Almost surely, 2^81503616490 is an apocalyptic number.

81503616490 is a deficient number, since it is larger than the sum of its proper divisors (65202893210).

81503616490 is a wasteful number, since it uses less digits than its factorization.

81503616490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8150361656.

The product of its (nonzero) digits is 155520, while the sum is 43.

The spelling of 81503616490 in words is "eighty-one billion, five hundred three million, six hundred sixteen thousand, four hundred ninety".