21201404517 has 24 divisors (see below), whose sum is σ = 31358756000. Its totient is φ = 13795735968.

The previous prime is 21201404509. The next prime is 21201404561. The reversal of 21201404517 is 71540410212.

21201404517 is a `hidden beast` number, since 2 + 1 + 2 + 0 + 140 + 4 + 517 = 666.

It is not a de Polignac number, because 21201404517 - 2³ = 21201404509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201404017) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 545859 + ... + 583407.

Almost surely, 2^21201404517 is an apocalyptic number.

It is an amenable number.

21201404517 is a deficient number, since it is larger than the sum of its proper divisors (10157351483).

21201404517 is a wasteful number, since it uses less digits than its factorization.

21201404517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39057 (or 39054 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

Adding to 21201404517 its reverse (71540410212), we get a palindrome (92741814729).

The spelling of 21201404517 in words is "twenty-one billion, two hundred one million, four hundred four thousand, five hundred seventeen".