21305414987 has 8 divisors (see below), whose sum is σ = 21394045296. Its totient is φ = 21216920032.

The previous prime is 21305414903. The next prime is 21305415017. The reversal of 21305414987 is 78941450312.

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 21305414987 - 2⁸ = 21305414731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21305414387) 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, 287948 + ... + 354294.

It is an arithmetic number, because the mean of its divisors is an integer number (2674255662).

Almost surely, 2^21305414987 is an apocalyptic number.

21305414987 is a deficient number, since it is larger than the sum of its proper divisors (88630309).

21305414987 is a wasteful number, since it uses less digits than its factorization.

21305414987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67677.

The product of its (nonzero) digits is 241920, while the sum is 44.

The spelling of 21305414987 in words is "twenty-one billion, three hundred five million, four hundred fourteen thousand, nine hundred eighty-seven".