6406207721 has 8 divisors (see below), whose sum is σ = 6436088064. Its totient is φ = 6376397760.

The previous prime is 6406207681. The next prime is 6406207727. The reversal of 6406207721 is 1277026046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6406207721 - 2⁶ = 6406207657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6406207727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 169460 + ... + 203786.

It is an arithmetic number, because the mean of its divisors is an integer number (804511008).

Almost surely, 2^6406207721 is an apocalyptic number.

It is an amenable number.

6406207721 is a deficient number, since it is larger than the sum of its proper divisors (29880343).

6406207721 is a wasteful number, since it uses less digits than its factorization.

6406207721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35191.

The product of its (nonzero) digits is 28224, while the sum is 35.

The square root of 6406207721 is about 80038.7888526557. The cubic root of 6406207721 is about 1857.2356246427.

The spelling of 6406207721 in words is "six billion, four hundred six million, two hundred seven thousand, seven hundred twenty-one".