21313501 has 8 divisors (see below), whose sum is σ = 23422464. Its totient is φ = 19233120.

The previous prime is 21313493. The next prime is 21313531. The reversal of 21313501 is 10531312.

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 21313501 - 2³ = 21313493 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 (21313531) 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, 5565 + ... + 8578.

It is an arithmetic number, because the mean of its divisors is an integer number (2927808).

Almost surely, 2^21313501 is an apocalyptic number.

It is an amenable number.

21313501 is a deficient number, since it is larger than the sum of its proper divisors (2108963).

21313501 is a wasteful number, since it uses less digits than its factorization.

21313501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14291.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 21313501 is about 4616.6547412602. The cubic root of 21313501 is about 277.2585395198.

Adding to 21313501 its reverse (10531312), we get a palindrome (31844813).

The spelling of 21313501 in words is "twenty-one million, three hundred thirteen thousand, five hundred one".