21000042122 has 32 divisors (see below), whose sum is σ = 32870449920. Its totient is φ = 10053201600.

The previous prime is 21000042083. The next prime is 21000042143. The reversal of 21000042122 is 22124000012.

It is a super-3 number, since 3×21000042122³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21000042097 and 21000042106.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1788872 + ... + 1800572.

It is an arithmetic number, because the mean of its divisors is an integer number (1027201560).

Almost surely, 2^21000042122 is an apocalyptic number.

21000042122 is a deficient number, since it is larger than the sum of its proper divisors (11870407798).

21000042122 is a wasteful number, since it uses less digits than its factorization.

21000042122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12126.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21000042122 its reverse (22124000012), we get a palindrome (43124042134).

The spelling of 21000042122 in words is "twenty-one billion, forty-two thousand, one hundred twenty-two".