646262021 has 8 divisors (see below), whose sum is σ = 688872600. Its totient is φ = 604162048.

The previous prime is 646262011. The next prime is 646262033. The reversal of 646262021 is 120262646.

It can be written as a sum of positive squares in 4 ways, for example, as 86229796 + 560032225 = 9286^2 + 23665^2 .

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

It is not a de Polignac number, because 646262021 - 2¹⁴ = 646245637 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 (646262011) 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, 125036 + ... + 130101.

It is an arithmetic number, because the mean of its divisors is an integer number (86109075).

Almost surely, 2^646262021 is an apocalyptic number.

It is an amenable number.

646262021 is a deficient number, since it is larger than the sum of its proper divisors (42610579).

646262021 is a wasteful number, since it uses less digits than its factorization.

646262021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255303.

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 646262021 is about 25421.6840708872. The cubic root of 646262021 is about 864.5754076886.

The spelling of 646262021 in words is "six hundred forty-six million, two hundred sixty-two thousand, twenty-one".