21115515510042 has 32 divisors (see below), whose sum is σ = 42833498886144. Its totient is φ = 6938129343600.

The previous prime is 21115515510031. The next prime is 21115515510091. The reversal of 21115515510042 is 24001551551112.

It is a happy number.

It is a super-3 number, since 3×21115515510042³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21115515509985 and 21115515510012.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2050978 + ... + 6814509.

It is an arithmetic number, because the mean of its divisors is an integer number (1338546840192).

Almost surely, 2^{21115515510042} is an apocalyptic number.

21115515510042 is an abundant number, since it is smaller than the sum of its proper divisors (21717983376102).

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

21115515510042 is a wasteful number, since it uses less digits than its factorization.

21115515510042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8871154.

The product of its (nonzero) digits is 10000, while the sum is 33.

The spelling of 21115515510042 in words is "twenty-one trillion, one hundred fifteen billion, five hundred fifteen million, five hundred ten thousand, forty-two".