21215240124 has 96 divisors (see below), whose sum is σ = 53628939840. Its totient is φ = 6488875008.

The previous prime is 21215240069. The next prime is 21215240161. The reversal of 21215240124 is 42104251212.

It is a super-3 number, since 3×21215240124³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21215240094 and 21215240103.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31523052 + ... + 31523724.

It is an arithmetic number, because the mean of its divisors is an integer number (558634790).

Almost surely, 2^21215240124 is an apocalyptic number.

It is an amenable number.

21215240124 is an abundant number, since it is smaller than the sum of its proper divisors (32413699716).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21215240124 is a wasteful number, since it uses less digits than its factorization.

21215240124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1599 (or 1597 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

Adding to 21215240124 its reverse (42104251212), we get a palindrome (63319491336).

The spelling of 21215240124 in words is "twenty-one billion, two hundred fifteen million, two hundred forty thousand, one hundred twenty-four".