21200357 has 4 divisors (see below), whose sum is σ = 21216000. Its totient is φ = 21184716.

The previous prime is 21200329. The next prime is 21200369. The reversal of 21200357 is 75300212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21200357 - 2¹² = 21196261 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 (21206357) 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, 5573 + ... + 8570.

It is an arithmetic number, because the mean of its divisors is an integer number (5304000).

Almost surely, 2^21200357 is an apocalyptic number.

It is an amenable number.

21200357 is a deficient number, since it is larger than the sum of its proper divisors (15643).

21200357 is a wasteful number, since it uses less digits than its factorization.

21200357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15642.

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 21200357 is about 4604.3845408480. The cubic root of 21200357 is about 276.7670542624.

Adding to 21200357 its reverse (75300212), we get a palindrome (96500569).

The spelling of 21200357 in words is "twenty-one million, two hundred thousand, three hundred fifty-seven".