15956148821 has 4 divisors (see below), whose sum is σ = 15957890700. Its totient is φ = 15954406944.

The previous prime is 15956148773. The next prime is 15956148827. The reversal of 15956148821 is 12884165951.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12884165951 = 15473 ⋅832687.

It can be written as a sum of positive squares in 2 ways, for example, as 5641512100 + 10314636721 = 75110^2 + 101561^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15956148821 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15956148821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15956148827) 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, 857126 + ... + 875543.

It is an arithmetic number, because the mean of its divisors is an integer number (3989472675).

Almost surely, 2^15956148821 is an apocalyptic number.

It is an amenable number.

15956148821 is a deficient number, since it is larger than the sum of its proper divisors (1741879).

15956148821 is an equidigital number, since it uses as much as digits as its factorization.

15956148821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1741878.

The product of its digits is 691200, while the sum is 50.

The spelling of 15956148821 in words is "fifteen billion, nine hundred fifty-six million, one hundred forty-eight thousand, eight hundred twenty-one".