15551320645 has 8 divisors (see below), whose sum is σ = 21327525504. Its totient is φ = 10663762704.

The previous prime is 15551320633. The next prime is 15551320667. The reversal of 15551320645 is 54602315551.

It is a happy number.

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

It is not a de Polignac number, because 15551320645 - 2⁷ = 15551320517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 222161689 + ... + 222161758.

It is an arithmetic number, because the mean of its divisors is an integer number (2665940688).

Almost surely, 2^15551320645 is an apocalyptic number.

It is an amenable number.

15551320645 is a deficient number, since it is larger than the sum of its proper divisors (5776204859).

15551320645 is an equidigital number, since it uses as much as digits as its factorization.

15551320645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444323459.

The product of its (nonzero) digits is 90000, while the sum is 37.

The spelling of 15551320645 in words is "fifteen billion, five hundred fifty-one million, three hundred twenty thousand, six hundred forty-five".