21146623647 has 8 divisors (see below), whose sum is σ = 28727488944. Its totient is φ = 13831753728.

The previous prime is 21146623643. The next prime is 21146623691. The reversal of 21146623647 is 74632664112.

It is a happy number.

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

It is not a de Polignac number, because 21146623647 - 2² = 21146623643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21146623599 and 21146623608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21146623643) 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, 66498658 + ... + 66498975.

It is an arithmetic number, because the mean of its divisors is an integer number (3590936118).

Almost surely, 2^21146623647 is an apocalyptic number.

21146623647 is a deficient number, since it is larger than the sum of its proper divisors (7580865297).

21146623647 is a wasteful number, since it uses less digits than its factorization.

21146623647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132997689.

The product of its digits is 290304, while the sum is 42.

The spelling of 21146623647 in words is "twenty-one billion, one hundred forty-six million, six hundred twenty-three thousand, six hundred forty-seven".