81640482621 has 8 divisors (see below), whose sum is σ = 109684923744. Its totient is φ = 54011514960.

The previous prime is 81640482619. The next prime is 81640482631. The reversal of 81640482621 is 12628404618.

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

It is not a de Polignac number, because 81640482621 - 2¹ = 81640482619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81640482631) 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, 103867906 + ... + 103868691.

It is an arithmetic number, because the mean of its divisors is an integer number (13710615468).

Almost surely, 2^81640482621 is an apocalyptic number.

It is an amenable number.

81640482621 is a deficient number, since it is larger than the sum of its proper divisors (28044441123).

81640482621 is a wasteful number, since it uses less digits than its factorization.

81640482621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207736731.

The product of its (nonzero) digits is 147456, while the sum is 42.

The spelling of 81640482621 in words is "eighty-one billion, six hundred forty million, four hundred eighty-two thousand, six hundred twenty-one".