647406221 has 16 divisors (see below), whose sum is σ = 808151040. Its totient is φ = 503850480.

The previous prime is 647406173. The next prime is 647406229. The reversal of 647406221 is 122604746.

It is not a de Polignac number, because 647406221 - 2⁶ = 647406157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647406229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63560 + ... + 73038.

It is an arithmetic number, because the mean of its divisors is an integer number (50509440).

Almost surely, 2^647406221 is an apocalyptic number.

It is an amenable number.

647406221 is a deficient number, since it is larger than the sum of its proper divisors (160744819).

647406221 is a wasteful number, since it uses less digits than its factorization.

647406221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10384.

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 647406221 is about 25444.1785286930. The cubic root of 647406221 is about 865.0853473652.

The spelling of 647406221 in words is "six hundred forty-seven million, four hundred six thousand, two hundred twenty-one".