21601523403 has 12 divisors (see below), whose sum is σ = 31314847408. Its totient is φ = 14349024720.

The previous prime is 21601523347. The next prime is 21601523417. The reversal of 21601523403 is 30432510612.

21601523403 is a `hidden beast` number, since 2 + 1 + 601 + 52 + 3 + 4 + 0 + 3 = 666.

It is not a de Polignac number, because 21601523403 - 2¹⁷ = 21601392331 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21601523423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4329943 + ... + 4334928.

Almost surely, 2^21601523403 is an apocalyptic number.

21601523403 is a deficient number, since it is larger than the sum of its proper divisors (9713324005).

21601523403 is a wasteful number, since it uses less digits than its factorization.

21601523403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8665154 (or 8665151 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The spelling of 21601523403 in words is "twenty-one billion, six hundred one million, five hundred twenty-three thousand, four hundred three".