1861551328215 has 8 divisors (see below), whose sum is σ = 2978482125168. Its totient is φ = 992827375040.

The previous prime is 1861551328201. The next prime is 1861551328223. The reversal of 1861551328215 is 5128231551681.

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

It is not a de Polignac number, because 1861551328215 - 2⁴ = 1861551328199 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62051710926 + ... + 62051710955.

It is an arithmetic number, because the mean of its divisors is an integer number (372310265646).

Almost surely, 2^{1861551328215} is an apocalyptic number.

1861551328215 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1861551328215 is a deficient number, since it is larger than the sum of its proper divisors (1116930796953).

1861551328215 is a wasteful number, since it uses less digits than its factorization.

1861551328215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124103421889.

The product of its digits is 576000, while the sum is 48.

Adding to 1861551328215 its reverse (5128231551681), we get a palindrome (6989782879896).

The spelling of 1861551328215 in words is "one trillion, eight hundred sixty-one billion, five hundred fifty-one million, three hundred twenty-eight thousand, two hundred fifteen".