21402142517 has 8 divisors (see below), whose sum is σ = 24804093312. Its totient is φ = 18086317200.

The previous prime is 21402142453. The next prime is 21402142529. The reversal of 21402142517 is 71524120412.

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

It is not a de Polignac number, because 21402142517 - 2⁶ = 21402142453 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21402142517.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402142217) 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, 21530834 + ... + 21531827.

It is an arithmetic number, because the mean of its divisors is an integer number (3100511664).

Almost surely, 2^21402142517 is an apocalyptic number.

It is an amenable number.

21402142517 is a deficient number, since it is larger than the sum of its proper divisors (3401950795).

21402142517 is an equidigital number, since it uses as much as digits as its factorization.

21402142517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43062739.

The product of its (nonzero) digits is 4480, while the sum is 29.

Adding to 21402142517 its reverse (71524120412), we get a palindrome (92926262929).

The spelling of 21402142517 in words is "twenty-one billion, four hundred two million, one hundred forty-two thousand, five hundred seventeen".