21155510202 has 24 divisors (see below), whose sum is σ = 43485484896. Its totient is φ = 6861243888.

The previous prime is 21155510183. The next prime is 21155510227. The reversal of 21155510202 is 20201555112.

It is a super-2 number, since 2×21155510202² (a number of 21 digits) contains 22 as substring.

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, 1279558 + ... + 1295985.

It is an arithmetic number, because the mean of its divisors is an integer number (1811895204).

Almost surely, 2^21155510202 is an apocalyptic number.

21155510202 is an abundant number, since it is smaller than the sum of its proper divisors (22329974694).

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

21155510202 is a wasteful number, since it uses less digits than its factorization.

21155510202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2575622 (or 2575585 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 24.

The spelling of 21155510202 in words is "twenty-one billion, one hundred fifty-five million, five hundred ten thousand, two hundred two".