21193213811 has 32 divisors (see below), whose sum is σ = 26693253120. Its totient is φ = 16345929600.

The previous prime is 21193213807. The next prime is 21193213823. The reversal of 21193213811 is 11831239112.

It is a happy number.

It is not a de Polignac number, because 21193213811 - 2² = 21193213807 is a prime.

It is a super-2 number, since 2×21193213811² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21193213801) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3272885 + ... + 3279353.

It is an arithmetic number, because the mean of its divisors is an integer number (834164160).

Almost surely, 2^21193213811 is an apocalyptic number.

21193213811 is a deficient number, since it is larger than the sum of its proper divisors (5500039309).

21193213811 is a wasteful number, since it uses less digits than its factorization.

21193213811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6915.

The product of its digits is 2592, while the sum is 32.

The spelling of 21193213811 in words is "twenty-one billion, one hundred ninety-three million, two hundred thirteen thousand, eight hundred eleven".