21287207953 has 8 divisors (see below), whose sum is σ = 23254715520. Its totient is φ = 19325084880.

The previous prime is 21287207939. The next prime is 21287207957. The reversal of 21287207953 is 35970278212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21287207953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21287207957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1337850 + ... + 1353667.

It is an arithmetic number, because the mean of its divisors is an integer number (2906839440).

Almost surely, 2^21287207953 is an apocalyptic number.

It is an amenable number.

21287207953 is a deficient number, since it is larger than the sum of its proper divisors (1967507567).

21287207953 is a wasteful number, since it uses less digits than its factorization.

21287207953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2692247.

The product of its (nonzero) digits is 423360, while the sum is 46.

The spelling of 21287207953 in words is "twenty-one billion, two hundred eighty-seven million, two hundred seven thousand, nine hundred fifty-three".