6401721109 has 8 divisors (see below), whose sum is σ = 7316749440. Its totient is φ = 5486816976.

The previous prime is 6401721103. The next prime is 6401721113. The reversal of 6401721109 is 9011271046.

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 6401721109 - 2³ = 6401721101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6401721101) 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, 149127 + ... + 187195.

It is an arithmetic number, because the mean of its divisors is an integer number (914593680).

Almost surely, 2^6401721109 is an apocalyptic number.

It is an amenable number.

6401721109 is a deficient number, since it is larger than the sum of its proper divisors (915028331).

6401721109 is a wasteful number, since it uses less digits than its factorization.

6401721109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62099.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 6401721109 is about 80010.7562081499. The cubic root of 6401721109 is about 1856.8019493682.

The spelling of 6401721109 in words is "six billion, four hundred one million, seven hundred twenty-one thousand, one hundred nine".