15800721982 has 4 divisors (see below), whose sum is σ = 23701082976. Its totient is φ = 7900360990.

The previous prime is 15800721913. The next prime is 15800721997. The reversal of 15800721982 is 28912700851.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3950180494 + ... + 3950180497.

It is an arithmetic number, because the mean of its divisors is an integer number (5925270744).

Almost surely, 2^15800721982 is an apocalyptic number.

15800721982 is a deficient number, since it is larger than the sum of its proper divisors (7900360994).

15800721982 is an equidigital number, since it uses as much as digits as its factorization.

15800721982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7900360993.

The product of its (nonzero) digits is 80640, while the sum is 43.

The spelling of 15800721982 in words is "fifteen billion, eight hundred million, seven hundred twenty-one thousand, nine hundred eighty-two".