21423642666437 has 8 divisors (see below), whose sum is σ = 23373296971200. Its totient is φ = 19474330099360.

The previous prime is 21423642666379. The next prime is 21423642666457. The reversal of 21423642666437 is 73466624632412.

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 21423642666437 - 2⁶ = 21423642666373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21423642666457) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85303328 + ... + 85554105.

It is an arithmetic number, because the mean of its divisors is an integer number (2921662121400).

Almost surely, 2^{21423642666437} is an apocalyptic number.

It is an amenable number.

21423642666437 is a deficient number, since it is larger than the sum of its proper divisors (1949654304763).

21423642666437 is a wasteful number, since it uses less digits than its factorization.

21423642666437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170868843.

The product of its digits is 41803776, while the sum is 56.

The spelling of 21423642666437 in words is "twenty-one trillion, four hundred twenty-three billion, six hundred forty-two million, six hundred sixty-six thousand, four hundred thirty-seven".