21434434442143 has 4 divisors (see below), whose sum is σ = 21455428012648. Its totient is φ = 21413440871640.

The previous prime is 21434434442129. The next prime is 21434434442147. The reversal of 21434434442143 is 34124443443412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21434434442143 is a prime.

It is a super-2 number, since 2×21434434442143² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21434434442143.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21434434442147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10496783721 + ... + 10496785762.

It is an arithmetic number, because the mean of its divisors is an integer number (5363857003162).

Almost surely, 2^{21434434442143} is an apocalyptic number.

21434434442143 is a deficient number, since it is larger than the sum of its proper divisors (20993570505).

21434434442143 is a wasteful number, since it uses less digits than its factorization.

21434434442143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20993570504.

The product of its digits is 1769472, while the sum is 43.

Adding to 21434434442143 its reverse (34124443443412), we get a palindrome (55558877885555).

The spelling of 21434434442143 in words is "twenty-one trillion, four hundred thirty-four billion, four hundred thirty-four million, four hundred forty-two thousand, one hundred forty-three".