21315303501 has 8 divisors (see below), whose sum is σ = 29916215520. Its totient is φ = 13462296912.

The previous prime is 21315303497. The next prime is 21315303517. The reversal of 21315303501 is 10530351312.

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

It is not a de Polignac number, because 21315303501 - 2² = 21315303497 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21315303701) 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, 186976290 + ... + 186976403.

It is an arithmetic number, because the mean of its divisors is an integer number (3739526940).

Almost surely, 2^21315303501 is an apocalyptic number.

It is an amenable number.

21315303501 is a deficient number, since it is larger than the sum of its proper divisors (8600912019).

21315303501 is a wasteful number, since it uses less digits than its factorization.

21315303501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373952715.

The product of its (nonzero) digits is 1350, while the sum is 24.

Adding to 21315303501 its reverse (10530351312), we get a palindrome (31845654813).

The spelling of 21315303501 in words is "twenty-one billion, three hundred fifteen million, three hundred three thousand, five hundred one".