21420403011 has 24 divisors (see below), whose sum is σ = 35423531520. Its totient is φ = 12218468976.

The previous prime is 21420402979. The next prime is 21420403021. The reversal of 21420403011 is 11030402412.

It is not a de Polignac number, because 21420403011 - 2⁵ = 21420402979 is a prime.

It is a super-2 number, since 2×21420403011² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21420403021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 266491 + ... + 337428.

It is an arithmetic number, because the mean of its divisors is an integer number (1475980480).

Almost surely, 2^21420403011 is an apocalyptic number.

21420403011 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21420403011 is a deficient number, since it is larger than the sum of its proper divisors (14003128509).

21420403011 is a wasteful number, since it uses less digits than its factorization.

21420403011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 604495 (or 604492 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21420403011 its reverse (11030402412), we get a palindrome (32450805423).

The spelling of 21420403011 in words is "twenty-one billion, four hundred twenty million, four hundred three thousand, eleven".