21010533402511 has 4 divisors (see below), whose sum is σ = 21203290589800. Its totient is φ = 20817776215224.

The previous prime is 21010533402457. The next prime is 21010533402517. The reversal of 21010533402511 is 11520433501012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21010533402511 - 2¹⁵ = 21010533369743 is a prime.

It is a super-2 number, since 2×21010533402511² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21010533402511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010533402517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96378593481 + ... + 96378593698.

It is an arithmetic number, because the mean of its divisors is an integer number (5300822647450).

Almost surely, 2^{21010533402511} is an apocalyptic number.

21010533402511 is a deficient number, since it is larger than the sum of its proper divisors (192757187289).

21010533402511 is a wasteful number, since it uses less digits than its factorization.

21010533402511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192757187288.

The product of its (nonzero) digits is 3600, while the sum is 28.

Adding to 21010533402511 its reverse (11520433501012), we get a palindrome (32530966903523).

The spelling of 21010533402511 in words is "twenty-one trillion, ten billion, five hundred thirty-three million, four hundred two thousand, five hundred eleven".