5001666421 has 2 divisors, whose sum is σ = 5001666422. Its totient is φ = 5001666420.

The previous prime is 5001666367. The next prime is 5001666433. The reversal of 5001666421 is 1246661005.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3870084100 + 1131582321 = 62210^2 + 33639^2 .

It is a cyclic number.

It is not a de Polignac number, because 5001666421 - 2¹³ = 5001658229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5001666451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2500833210 + 2500833211.

It is an arithmetic number, because the mean of its divisors is an integer number (2500833211).

Almost surely, 2^5001666421 is an apocalyptic number.

It is an amenable number.

5001666421 is a deficient number, since it is larger than the sum of its proper divisors (1).

5001666421 is an equidigital number, since it uses as much as digits as its factorization.

5001666421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 5001666421 is about 70722.4605129092. The cubic root of 5001666421 is about 1710.1658948978.

The spelling of 5001666421 in words is "five billion, one million, six hundred sixty-six thousand, four hundred twenty-one".