21155112002 has 16 divisors (see below), whose sum is σ = 32550629760. Its totient is φ = 10306885488.

The previous prime is 21155111987. The next prime is 21155112023. The reversal of 21155112002 is 20021155112.

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, 474377 + ... + 517052.

It is an arithmetic number, because the mean of its divisors is an integer number (2034414360).

Almost surely, 2^21155112002 is an apocalyptic number.

21155112002 is a deficient number, since it is larger than the sum of its proper divisors (11395517758).

21155112002 is a wasteful number, since it uses less digits than its factorization.

21155112002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 991705.

The product of its (nonzero) digits is 200, while the sum is 20.

Adding to 21155112002 its reverse (20021155112), we get a palindrome (41176267114).

The spelling of 21155112002 in words is "twenty-one billion, one hundred fifty-five million, one hundred twelve thousand, two".