21251423678 has 8 divisors (see below), whose sum is σ = 32068017072. Its totient is φ = 10562084656.

The previous prime is 21251423671. The next prime is 21251423681. The reversal of 21251423678 is 87632415212.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21251423671) 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, 31813175 + ... + 31813842.

It is an arithmetic number, because the mean of its divisors is an integer number (4008502134).

Almost surely, 2^21251423678 is an apocalyptic number.

21251423678 is a deficient number, since it is larger than the sum of its proper divisors (10816593394).

21251423678 is a wasteful number, since it uses less digits than its factorization.

21251423678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63627186.

The product of its digits is 161280, while the sum is 41.

The spelling of 21251423678 in words is "twenty-one billion, two hundred fifty-one million, four hundred twenty-three thousand, six hundred seventy-eight".