21511041513542 has 32 divisors (see below), whose sum is σ = 37922489478720. Its totient is φ = 8958068052480.

The previous prime is 21511041513527. The next prime is 21511041513553. The reversal of 21511041513542 is 24531514011512.

It is a happy number.

It is a congruent number.

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, 26890367 + ... + 27678762.

It is an arithmetic number, because the mean of its divisors is an integer number (1185077796210).

Almost surely, 2^{21511041513542} is an apocalyptic number.

21511041513542 is a deficient number, since it is larger than the sum of its proper divisors (16411447965178).

21511041513542 is a wasteful number, since it uses less digits than its factorization.

21511041513542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54569936.

The product of its (nonzero) digits is 24000, while the sum is 35.

The spelling of 21511041513542 in words is "twenty-one trillion, five hundred eleven billion, forty-one million, five hundred thirteen thousand, five hundred forty-two".