21432142997 has 4 divisors (see below), whose sum is σ = 21433814880. Its totient is φ = 21430471116.

The previous prime is 21432142993. The next prime is 21432143003. The reversal of 21432142997 is 79924123412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21432142997 - 2² = 21432142993 is a prime.

It is a super-2 number, since 2×21432142997² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21432142993) 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, 816563 + ... + 842400.

It is an arithmetic number, because the mean of its divisors is an integer number (5358453720).

Almost surely, 2^21432142997 is an apocalyptic number.

It is an amenable number.

21432142997 is a deficient number, since it is larger than the sum of its proper divisors (1671883).

21432142997 is a wasteful number, since it uses less digits than its factorization.

21432142997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1671882.

The product of its digits is 217728, while the sum is 44.

The spelling of 21432142997 in words is "twenty-one billion, four hundred thirty-two million, one hundred forty-two thousand, nine hundred ninety-seven".