21036407 has 8 divisors (see below), whose sum is σ = 24231936. Its totient is φ = 17888472.

The previous prime is 21036371. The next prime is 21036409. The reversal of 21036407 is 70463012.

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

It is not a de Polignac number, because 21036407 - 2⁸ = 21036151 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 (21036409) 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, 10943 + ... + 12720.

It is an arithmetic number, because the mean of its divisors is an integer number (3028992).

Almost surely, 2^21036407 is an apocalyptic number.

21036407 is a deficient number, since it is larger than the sum of its proper divisors (3195529).

21036407 is a wasteful number, since it uses less digits than its factorization.

21036407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23797.

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 21036407 is about 4586.5463041378. The cubic root of 21036407 is about 276.0517607536.

Adding to 21036407 its reverse (70463012), we get a palindrome (91499419).

The spelling of 21036407 in words is "twenty-one million, thirty-six thousand, four hundred seven".