6649399 has 2 divisors, whose sum is σ = 6649400. Its totient is φ = 6649398.

The previous prime is 6649393. The next prime is 6649403. The reversal of 6649399 is 9939466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6649399 - 2⁵ = 6649367 is a prime.

It is a super-2 number, since 2×6649399² = 88429014122402, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6649393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3324699 + 3324700.

It is an arithmetic number, because the mean of its divisors is an integer number (3324700).

Almost surely, 2^6649399 is an apocalyptic number.

6649399 is a deficient number, since it is larger than the sum of its proper divisors (1).

6649399 is an equidigital number, since it uses as much as digits as its factorization.

6649399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 314928, while the sum is 46.

The square root of 6649399 is about 2578.6428601107. The cubic root of 6649399 is about 188.0445703139.

The spelling of 6649399 in words is "six million, six hundred forty-nine thousand, three hundred ninety-nine".