21011203242 has 24 divisors (see below), whose sum is σ = 46100533440. Its totient is φ = 6915079080.

The previous prime is 21011203231. The next prime is 21011203259. The reversal of 21011203242 is 24230211012.

It is a happy number.

21011203242 is a `hidden beast` number, since 210 + 11 + 203 + 242 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7386484 + ... + 7389327.

It is an arithmetic number, because the mean of its divisors is an integer number (1920855560).

Almost surely, 2^21011203242 is an apocalyptic number.

21011203242 is an abundant number, since it is smaller than the sum of its proper divisors (25089330198).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21011203242 is a wasteful number, since it uses less digits than its factorization.

21011203242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14775898 (or 14775895 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21011203242 its reverse (24230211012), we get a palindrome (45241414254).

The spelling of 21011203242 in words is "twenty-one billion, eleven million, two hundred three thousand, two hundred forty-two".