21155002555242 has 16 divisors (see below), whose sum is σ = 44536847484960. Its totient is φ = 6680527122672.

The previous prime is 21155002555217. The next prime is 21155002555249. The reversal of 21155002555242 is 24255520055112.

It is a super-2 number, since 2×21155002555242² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21155002555242.

It is not an unprimeable number, because it can be changed into a prime (21155002555249) by changing a digit.

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, 92785098813 + ... + 92785099040.

It is an arithmetic number, because the mean of its divisors is an integer number (2783552967810).

Almost surely, 2^{21155002555242} is an apocalyptic number.

21155002555242 is an abundant number, since it is smaller than the sum of its proper divisors (23381844929718).

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

21155002555242 is a wasteful number, since it uses less digits than its factorization.

21155002555242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185570197877.

The product of its (nonzero) digits is 200000, while the sum is 39.

The spelling of 21155002555242 in words is "twenty-one trillion, one hundred fifty-five billion, two million, five hundred fifty-five thousand, two hundred forty-two".