15856223842 has 4 divisors (see below), whose sum is σ = 23784335766. Its totient is φ = 7928111920.

The previous prime is 15856223837. The next prime is 15856223849. The reversal of 15856223842 is 24832265851.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24832265851 = 389 ⋅63836159.

It can be written as a sum of positive squares in only one way, i.e., 9668985561 + 6187238281 = 98331^2 + 78659^2 .

It is a junction number, because it is equal to n+sod(n) for n = 15856223792 and 15856223801.

It is not an unprimeable number, because it can be changed into a prime (15856223849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3964055959 + ... + 3964055962.

Almost surely, 2^15856223842 is an apocalyptic number.

15856223842 is a deficient number, since it is larger than the sum of its proper divisors (7928111924).

15856223842 is an equidigital number, since it uses as much as digits as its factorization.

15856223842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7928111923.

The product of its digits is 921600, while the sum is 46.

The spelling of 15856223842 in words is "fifteen billion, eight hundred fifty-six million, two hundred twenty-three thousand, eight hundred forty-two".