21213103455 has 96 divisors (see below), whose sum is σ = 40231002240. Its totient is φ = 10298695680.

The previous prime is 21213103423. The next prime is 21213103487. The reversal of 21213103455 is 55430131212.

21213103455 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 310 + 345 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (21213103423) and next prime (21213103487).

It is not a de Polignac number, because 21213103455 - 2⁵ = 21213103423 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2875011 + ... + 2882379.

It is an arithmetic number, because the mean of its divisors is an integer number (419072940).

Almost surely, 2^21213103455 is an apocalyptic number.

21213103455 is a deficient number, since it is larger than the sum of its proper divisors (19017898785).

21213103455 is a wasteful number, since it uses less digits than its factorization.

21213103455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7521 (or 7518 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

Adding to 21213103455 its reverse (55430131212), we get a palindrome (76643234667).

The spelling of 21213103455 in words is "twenty-one billion, two hundred thirteen million, one hundred three thousand, four hundred fifty-five".