7861221687 has 32 divisors (see below), whose sum is σ = 12016730880. Its totient is φ = 4527774720.

The previous prime is 7861221679. The next prime is 7861221701.

7861221687 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 7861221687 - 2³ = 7861221679 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7861221647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22362 + ... + 127367.

It is an arithmetic number, because the mean of its divisors is an integer number (375522840).

Almost surely, 2^7861221687 is an apocalyptic number.

7861221687 is a deficient number, since it is larger than the sum of its proper divisors (4155509193).

7861221687 is a wasteful number, since it uses less digits than its factorization.

7861221687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149823.

The product of its digits is 451584, while the sum is 48.

The square root of 7861221687 is about 88663.5307609617. The cubic root of 7861221687 is about 1988.3676155667.

The spelling of 7861221687 in words is "seven billion, eight hundred sixty-one million, two hundred twenty-one thousand, six hundred eighty-seven".