21102121654 has 16 divisors (see below), whose sum is σ = 32429453616. Its totient is φ = 10292371200.

The previous prime is 21102121637. The next prime is 21102121657. The reversal of 21102121654 is 45612120112.

21102121654 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102121657) 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, 950974 + ... + 972910.

It is an arithmetic number, because the mean of its divisors is an integer number (2026840851).

Almost surely, 2^21102121654 is an apocalyptic number.

21102121654 is a deficient number, since it is larger than the sum of its proper divisors (11327331962).

21102121654 is a wasteful number, since it uses less digits than its factorization.

21102121654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33711.

The product of its (nonzero) digits is 960, while the sum is 25.

Adding to 21102121654 its reverse (45612120112), we get a palindrome (66714241766).

The spelling of 21102121654 in words is "twenty-one billion, one hundred two million, one hundred twenty-one thousand, six hundred fifty-four".