6420996623 has 2 divisors, whose sum is σ = 6420996624. Its totient is φ = 6420996622.

The previous prime is 6420996583. The next prime is 6420996649. The reversal of 6420996623 is 3266990246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6420996623 - 2⁸ = 6420996367 is a prime.

It is a super-3 number, since 3×6420996623³ (a number of 30 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6420990623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3210498311 + 3210498312.

It is an arithmetic number, because the mean of its divisors is an integer number (3210498312).

Almost surely, 2^6420996623 is an apocalyptic number.

6420996623 is a deficient number, since it is larger than the sum of its proper divisors (1).

6420996623 is an equidigital number, since it uses as much as digits as its factorization.

6420996623 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 839808, while the sum is 47.

The square root of 6420996623 is about 80131.1214385522. The cubic root of 6420996623 is about 1858.6636856843.

The spelling of 6420996623 in words is "six billion, four hundred twenty million, nine hundred ninety-six thousand, six hundred twenty-three".