21315010551 has 8 divisors (see below), whose sum is σ = 28423997184. Its totient is φ = 14208015480.

The previous prime is 21315010523. The next prime is 21315010699. The reversal of 21315010551 is 15501051312.

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

It is not a de Polignac number, because 21315010551 - 2⁶ = 21315010487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21315010351) 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, 472735 + ... + 515856.

It is an arithmetic number, because the mean of its divisors is an integer number (3552999648).

Almost surely, 2^21315010551 is an apocalyptic number.

21315010551 is a deficient number, since it is larger than the sum of its proper divisors (7108986633).

21315010551 is an equidigital number, since it uses as much as digits as its factorization.

21315010551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 995781.

The product of its (nonzero) digits is 750, while the sum is 24.

Adding to 21315010551 its reverse (15501051312), we get a palindrome (36816061863).

The spelling of 21315010551 in words is "twenty-one billion, three hundred fifteen million, ten thousand, five hundred fifty-one".