21111402524 has 24 divisors (see below), whose sum is σ = 37196823888. Its totient is φ = 10483799040.

The previous prime is 21111402509. The next prime is 21111402527. The reversal of 21111402524 is 42520411112.

It is a self number, because there is not a number n which added to its sum of digits gives 21111402524.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111402527) 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, 1722779 + ... + 1734989.

It is an arithmetic number, because the mean of its divisors is an integer number (1549867662).

Almost surely, 2^21111402524 is an apocalyptic number.

It is an amenable number.

21111402524 is a deficient number, since it is larger than the sum of its proper divisors (16085421364).

21111402524 is a wasteful number, since it uses less digits than its factorization.

21111402524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15125 (or 15123 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 23.

Adding to 21111402524 its reverse (42520411112), we get a palindrome (63631813636).

The spelling of 21111402524 in words is "twenty-one billion, one hundred eleven million, four hundred two thousand, five hundred twenty-four".