21001364 has 6 divisors (see below), whose sum is σ = 36752394. Its totient is φ = 10500680.

The previous prime is 21001349. The next prime is 21001367. The reversal of 21001364 is 46310012.

It can be written as a sum of positive squares in only one way, i.e., 20976400 + 24964 = 4580^2 + 158^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2625167 + ... + 2625174.

It is an arithmetic number, because the mean of its divisors is an integer number (6125399).

Almost surely, 2^21001364 is an apocalyptic number.

It is an amenable number.

21001364 is a deficient number, since it is larger than the sum of its proper divisors (15751030).

21001364 is a wasteful number, since it uses less digits than its factorization.

21001364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5250345 (or 5250343 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21001364 is about 4582.7245171404. The cubic root of 21001364 is about 275.8983907986.

Adding to 21001364 its reverse (46310012), we get a palindrome (67311376).

The spelling of 21001364 in words is "twenty-one million, one thousand, three hundred sixty-four".