6450721 has 4 divisors (see below), whose sum is σ = 6479872. Its totient is φ = 6421572.

The previous prime is 6450707. The next prime is 6450727. The reversal of 6450721 is 1270546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6450721 - 2⁷ = 6450593 is a prime.

It is a super-2 number, since 2×6450721² = 83223602839682, which contains 22 as substring.

It is a Duffinian number.

6450721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6450727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14241 + ... + 14686.

It is an arithmetic number, because the mean of its divisors is an integer number (1619968).

Almost surely, 2^6450721 is an apocalyptic number.

It is an amenable number.

6450721 is a deficient number, since it is larger than the sum of its proper divisors (29151).

6450721 is a wasteful number, since it uses less digits than its factorization.

6450721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29150.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 6450721 is about 2539.8269626099. The cubic root of 6450721 is about 186.1527342232.

The spelling of 6450721 in words is "six million, four hundred fifty thousand, seven hundred twenty-one".