21420420099 has 32 divisors (see below), whose sum is σ = 32171973120. Its totient is φ = 12578362368.

The previous prime is 21420420097. The next prime is 21420420103. The reversal of 21420420099 is 99002402412.

It is not a de Polignac number, because 21420420099 - 2¹ = 21420420097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21420420097) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 347347 + ... + 404339.

It is an arithmetic number, because the mean of its divisors is an integer number (1005374160).

Almost surely, 2^21420420099 is an apocalyptic number.

21420420099 is a deficient number, since it is larger than the sum of its proper divisors (10751553021).

21420420099 is a wasteful number, since it uses less digits than its factorization.

21420420099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57451.

The product of its (nonzero) digits is 10368, while the sum is 33.

The spelling of 21420420099 in words is "twenty-one billion, four hundred twenty million, four hundred twenty thousand, ninety-nine".