21223988971 has 4 divisors (see below), whose sum is σ = 21366432000. Its totient is φ = 21081545944.

The previous prime is 21223988957. The next prime is 21223988999. The reversal of 21223988971 is 17988932212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21223988971 - 2²¹ = 21221891819 is a prime.

It is a super-2 number, since 2×21223988971² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21223988371) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 71221291 + ... + 71221588.

It is an arithmetic number, because the mean of its divisors is an integer number (5341608000).

Almost surely, 2^21223988971 is an apocalyptic number.

21223988971 is a deficient number, since it is larger than the sum of its proper divisors (142443029).

21223988971 is a wasteful number, since it uses less digits than its factorization.

21223988971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142443028.

The product of its digits is 870912, while the sum is 52.

The spelling of 21223988971 in words is "twenty-one billion, two hundred twenty-three million, nine hundred eighty-eight thousand, nine hundred seventy-one".