21121423402 has 16 divisors (see below), whose sum is σ = 31816422792. Its totient is φ = 10515997440.

The previous prime is 21121423327. The next prime is 21121423447. The reversal of 21121423402 is 20432412112.

It can be written as a sum of positive squares in 4 ways, for example, as 11924421601 + 9197001801 = 109199^2 + 95901^2 .

It is a super-2 number, since 2×21121423402² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 942358 + ... + 964510.

Almost surely, 2^21121423402 is an apocalyptic number.

21121423402 is a deficient number, since it is larger than the sum of its proper divisors (10694999390).

21121423402 is a wasteful number, since it uses less digits than its factorization.

21121423402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24153.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21121423402 its reverse (20432412112), we get a palindrome (41553835514).

The spelling of 21121423402 in words is "twenty-one billion, one hundred twenty-one million, four hundred twenty-three thousand, four hundred two".