21240555213 has 8 divisors (see below), whose sum is σ = 28527461568. Its totient is φ = 14057009504.

The previous prime is 21240555209. The next prime is 21240555247. The reversal of 21240555213 is 31255504212.

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 21240555213 - 2² = 21240555209 is a prime.

It is a super-2 number, since 2×21240555213² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240555263) 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, 25839681 + ... + 25840502.

It is an arithmetic number, because the mean of its divisors is an integer number (3565932696).

Almost surely, 2^21240555213 is an apocalyptic number.

It is an amenable number.

21240555213 is a deficient number, since it is larger than the sum of its proper divisors (7286906355).

21240555213 is a wasteful number, since it uses less digits than its factorization.

21240555213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51680323.

The product of its (nonzero) digits is 12000, while the sum is 30.

The spelling of 21240555213 in words is "twenty-one billion, two hundred forty million, five hundred fifty-five thousand, two hundred thirteen".