21210220124 has 24 divisors (see below), whose sum is σ = 37361248848. Its totient is φ = 10535736960.

The previous prime is 21210220123. The next prime is 21210220127. The reversal of 21210220124 is 42102201212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210220123) 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, 525032 + ... + 563984.

It is an arithmetic number, because the mean of its divisors is an integer number (1556718702).

Almost surely, 2^21210220124 is an apocalyptic number.

It is an amenable number.

21210220124 is a deficient number, since it is larger than the sum of its proper divisors (16151028724).

21210220124 is a wasteful number, since it uses less digits than its factorization.

21210220124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39845 (or 39843 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21210220124 its reverse (42102201212), we get a palindrome (63312421336).

The spelling of 21210220124 in words is "twenty-one billion, two hundred ten million, two hundred twenty thousand, one hundred twenty-four".