7519678921 has 2 divisors, whose sum is σ = 7519678922. Its totient is φ = 7519678920.

The previous prime is 7519678919. The next prime is 7519678939. The reversal of 7519678921 is 1298769157.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7510648896 + 9030025 = 86664^2 + 3005^2 .

It is a cyclic number.

It is not a de Polignac number, because 7519678921 - 2¹ = 7519678919 is a prime.

Together with 7519678919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (7519678321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3759839460 + 3759839461.

It is an arithmetic number, because the mean of its divisors is an integer number (3759839461).

Almost surely, 2^7519678921 is an apocalyptic number.

It is an amenable number.

7519678921 is a deficient number, since it is larger than the sum of its proper divisors (1).

7519678921 is an equidigital number, since it uses as much as digits as its factorization.

7519678921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1905120, while the sum is 55.

The square root of 7519678921 is about 86716.0822512180. The cubic root of 7519678921 is about 1959.1443336541.

The spelling of 7519678921 in words is "seven billion, five hundred nineteen million, six hundred seventy-eight thousand, nine hundred twenty-one".