21155240202 has 16 divisors (see below), whose sum is σ = 42335881632. Its totient is φ = 7047513200.

The previous prime is 21155240177. The next prime is 21155240261. The reversal of 21155240202 is 20204255112.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1047549 + ... + 1067552.

It is an arithmetic number, because the mean of its divisors is an integer number (2645992602).

Almost surely, 2^21155240202 is an apocalyptic number.

21155240202 is an abundant number, since it is smaller than the sum of its proper divisors (21180641430).

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

21155240202 is a wasteful number, since it uses less digits than its factorization.

21155240202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2116773.

The product of its (nonzero) digits is 1600, while the sum is 24.

Adding to 21155240202 its reverse (20204255112), we get a palindrome (41359495314).

The spelling of 21155240202 in words is "twenty-one billion, one hundred fifty-five million, two hundred forty thousand, two hundred two".