21156143493 has 8 divisors (see below), whose sum is σ = 29867496768. Its totient is φ = 13274442944.

The previous prime is 21156143483. The next prime is 21156143509. The reversal of 21156143493 is 39434165112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21156143493 - 2¹² = 21156139397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21156143483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 207413121 + ... + 207413222.

It is an arithmetic number, because the mean of its divisors is an integer number (3733437096).

Almost surely, 2^21156143493 is an apocalyptic number.

It is an amenable number.

21156143493 is a deficient number, since it is larger than the sum of its proper divisors (8711353275).

21156143493 is a wasteful number, since it uses less digits than its factorization.

21156143493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414826363.

The product of its digits is 77760, while the sum is 39.

The spelling of 21156143493 in words is "twenty-one billion, one hundred fifty-six million, one hundred forty-three thousand, four hundred ninety-three".