21121201050 has 24 divisors (see below), whose sum is σ = 52380578976. Its totient is φ = 5632320240.

The previous prime is 21121201009. The next prime is 21121201099. The reversal of 21121201050 is 5010212112.

It is a super-2 number, since 2×21121201050² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70403854 + ... + 70404153.

It is an arithmetic number, because the mean of its divisors is an integer number (2182524124).

Almost surely, 2^21121201050 is an apocalyptic number.

21121201050 is an abundant number, since it is smaller than the sum of its proper divisors (31259377926).

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

21121201050 is a wasteful number, since it uses less digits than its factorization.

21121201050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140808022 (or 140808017 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 15.

Adding to 21121201050 its reverse (5010212112), we get a palindrome (26131413162).

The spelling of 21121201050 in words is "twenty-one billion, one hundred twenty-one million, two hundred one thousand, fifty".