21540521351530 has 16 divisors (see below), whose sum is σ = 38773029837024. Its totient is φ = 8616188228560.

The previous prime is 21540521351519. The next prime is 21540521351537. The reversal of 21540521351530 is 3515312504512.

It is a self number, because there is not a number n which added to its sum of digits gives 21540521351530.

It is not an unprimeable number, because it can be changed into a prime (21540521351537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2366289 + ... + 6977131.

It is an arithmetic number, because the mean of its divisors is an integer number (2423314364814).

Almost surely, 2^{21540521351530} is an apocalyptic number.

21540521351530 is a deficient number, since it is larger than the sum of its proper divisors (17232508485494).

21540521351530 is a wasteful number, since it uses less digits than its factorization.

21540521351530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5078021.

The product of its (nonzero) digits is 90000, while the sum is 37.

The spelling of 21540521351530 in words is "twenty-one trillion, five hundred forty billion, five hundred twenty-one million, three hundred fifty-one thousand, five hundred thirty".