21403643355 has 48 divisors (see below), whose sum is σ = 39085956000. Its totient is φ = 10805142528.

The previous prime is 21403643341. The next prime is 21403643357. The reversal of 21403643355 is 55334630412.

21403643355 is a `hidden beast` number, since 2 + 1 + 4 + 0 + 3 + 643 + 3 + 5 + 5 = 666.

It is not a de Polignac number, because 21403643355 - 2⁵ = 21403643323 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21403643357) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1040611 + ... + 1060979.

It is an arithmetic number, because the mean of its divisors is an integer number (814290750).

Almost surely, 2^21403643355 is an apocalyptic number.

21403643355 is a deficient number, since it is larger than the sum of its proper divisors (17682312645).

21403643355 is a wasteful number, since it uses less digits than its factorization.

21403643355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21628 (or 21625 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 36.

The spelling of 21403643355 in words is "twenty-one billion, four hundred three million, six hundred forty-three thousand, three hundred fifty-five".