21002124124 has 6 divisors (see below), whose sum is σ = 36753717224. Its totient is φ = 10501062060.

The previous prime is 21002124109. The next prime is 21002124131. The reversal of 21002124124 is 42142120012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2625265512 + ... + 2625265519.

Almost surely, 2^21002124124 is an apocalyptic number.

It is an amenable number.

21002124124 is a deficient number, since it is larger than the sum of its proper divisors (15751593100).

21002124124 is a wasteful number, since it uses less digits than its factorization.

21002124124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5250531035 (or 5250531033 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21002124124 its reverse (42142120012), we get a palindrome (63144244136).

The spelling of 21002124124 in words is "twenty-one billion, two million, one hundred twenty-four thousand, one hundred twenty-four".