21218141547 has 6 divisors (see below), whose sum is σ = 30648426692. Its totient is φ = 14145427692.

The previous prime is 21218141533. The next prime is 21218141551. The reversal of 21218141547 is 74514181212.

21218141547 is a `hidden beast` number, since 2 + 121 + 81 + 415 + 47 = 666.

It is not a de Polignac number, because 21218141547 - 2²² = 21213947243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21218141557) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1178785633 + ... + 1178785650.

Almost surely, 2^21218141547 is an apocalyptic number.

21218141547 is a deficient number, since it is larger than the sum of its proper divisors (9430285145).

21218141547 is a wasteful number, since it uses less digits than its factorization.

21218141547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2357571289 (or 2357571286 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The spelling of 21218141547 in words is "twenty-one billion, two hundred eighteen million, one hundred forty-one thousand, five hundred forty-seven".