647221601 has 4 divisors (see below), whose sum is σ = 697007892. Its totient is φ = 597435312.

The previous prime is 647221583. The next prime is 647221657. The reversal of 647221601 is 106122746.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 360088576 + 287133025 = 18976^2 + 16945^2 .

It is a cyclic number.

It is not a de Polignac number, because 647221601 - 2¹⁴ = 647205217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647221901) 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, 24893126 + ... + 24893151.

It is an arithmetic number, because the mean of its divisors is an integer number (174251973).

Almost surely, 2^647221601 is an apocalyptic number.

It is an amenable number.

647221601 is a deficient number, since it is larger than the sum of its proper divisors (49786291).

647221601 is a wasteful number, since it uses less digits than its factorization.

647221601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49786290.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 647221601 is about 25440.5503281670. The cubic root of 647221601 is about 865.0031077884.

The spelling of 647221601 in words is "six hundred forty-seven million, two hundred twenty-one thousand, six hundred one".