21123243415 has 8 divisors (see below), whose sum is σ = 25349782608. Its totient is φ = 16897334400.

The previous prime is 21123243403. The next prime is 21123243443. The reversal of 21123243415 is 51434232112.

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

It is not a de Polignac number, because 21123243415 - 2⁷ = 21123243287 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80361 + ... + 220690.

It is an arithmetic number, because the mean of its divisors is an integer number (3168722826).

Almost surely, 2^21123243415 is an apocalyptic number.

21123243415 is a deficient number, since it is larger than the sum of its proper divisors (4226539193).

21123243415 is a wasteful number, since it uses less digits than its factorization.

21123243415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315089.

The product of its digits is 5760, while the sum is 28.

Adding to 21123243415 its reverse (51434232112), we get a palindrome (72557475527).

The spelling of 21123243415 in words is "twenty-one billion, one hundred twenty-three million, two hundred forty-three thousand, four hundred fifteen".