7687018421 has 2 divisors, whose sum is σ = 7687018422. Its totient is φ = 7687018420.

The previous prime is 7687018403. The next prime is 7687018433. The reversal of 7687018421 is 1248107867.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7518797521 + 168220900 = 86711^2 + 12970^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7687018421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7687018481) by changing a digit.

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 as a sum of consecutive naturals, namely, 3843509210 + 3843509211.

It is an arithmetic number, because the mean of its divisors is an integer number (3843509211).

Almost surely, 2^7687018421 is an apocalyptic number.

It is an amenable number.

7687018421 is a deficient number, since it is larger than the sum of its proper divisors (1).

7687018421 is an equidigital number, since it uses as much as digits as its factorization.

7687018421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 150528, while the sum is 44.

The square root of 7687018421 is about 87675.6432596876. The cubic root of 7687018421 is about 1973.5704804597.

The spelling of 7687018421 in words is "seven billion, six hundred eighty-seven million, eighteen thousand, four hundred twenty-one".