21203701 has 8 divisors (see below), whose sum is σ = 21894840. Its totient is φ = 20518848.

The previous prime is 21203681. The next prime is 21203711. The reversal of 21203701 is 10730212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 17631601 + 3572100 = 4199^2 + 1890^2 .

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 21203701 - 2¹³ = 21195509 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 (21203711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5835 + ... + 8743.

It is an arithmetic number, because the mean of its divisors is an integer number (2736855).

Almost surely, 2^21203701 is an apocalyptic number.

It is an amenable number.

21203701 is a deficient number, since it is larger than the sum of its proper divisors (691139).

21203701 is a wasteful number, since it uses less digits than its factorization.

21203701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3143.

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 21203701 is about 4604.7476586671. The cubic root of 21203701 is about 276.7816052811.

Adding to 21203701 its reverse (10730212), we get a palindrome (31933913).

It can be divided in two parts, 21203 and 701, that added together give a square (21904 = 148²).

The spelling of 21203701 in words is "twenty-one million, two hundred three thousand, seven hundred one".