6420999 has 32 divisors (see below), whose sum is σ = 9805824. Its totient is φ = 3709440.

The previous prime is 6420991. The next prime is 6421001. The reversal of 6420999 is 9990246.

6420999 is digitally balanced in base 3 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6420999 - 2³ = 6420991 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6420991) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 56767 + ... + 56879.

It is an arithmetic number, because the mean of its divisors is an integer number (306432).

Almost surely, 2^6420999 is an apocalyptic number.

6420999 is a deficient number, since it is larger than the sum of its proper divisors (3384825).

6420999 is a wasteful number, since it uses less digits than its factorization.

6420999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207.

The product of its (nonzero) digits is 34992, while the sum is 39.

The square root of 6420999 is about 2533.9690211208. The cubic root of 6420999 is about 185.8663915038.

The spelling of 6420999 in words is "six million, four hundred twenty thousand, nine hundred ninety-nine".