21500121222542 has 16 divisors (see below), whose sum is σ = 33128294522640. Its totient is φ = 10457470173888.

The previous prime is 21500121222521. The next prime is 21500121222577. The reversal of 21500121222542 is 24522212100512.

It is a super-3 number, since 3×21500121222542³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28067567 + ... + 28823402.

It is an arithmetic number, because the mean of its divisors is an integer number (2070518407665).

Almost surely, 2^{21500121222542} is an apocalyptic number.

21500121222542 is a deficient number, since it is larger than the sum of its proper divisors (11628173300098).

21500121222542 is a wasteful number, since it uses less digits than its factorization.

21500121222542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56896115.

The product of its (nonzero) digits is 6400, while the sum is 29.

The spelling of 21500121222542 in words is "twenty-one trillion, five hundred billion, one hundred twenty-one million, two hundred twenty-two thousand, five hundred forty-two".