21430433121 has 16 divisors (see below), whose sum is σ = 30669182784. Its totient is φ = 13262344704.

The previous prime is 21430433117. The next prime is 21430433153. The reversal of 21430433121 is 12133403412.

It is a happy number.

It is not a de Polignac number, because 21430433121 - 2² = 21430433117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21430433091 and 21430433100.

It is not an unprimeable number, because it can be changed into a prime (21430433191) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2874391 + ... + 2881836.

It is an arithmetic number, because the mean of its divisors is an integer number (1916823924).

Almost surely, 2^21430433121 is an apocalyptic number.

It is an amenable number.

21430433121 is a deficient number, since it is larger than the sum of its proper divisors (9238749663).

21430433121 is a wasteful number, since it uses less digits than its factorization.

21430433121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5756320.

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 21430433121 its reverse (12133403412), we get a palindrome (33563836533).

The spelling of 21430433121 in words is "twenty-one billion, four hundred thirty million, four hundred thirty-three thousand, one hundred twenty-one".