21267600978064 has 40 divisors (see below), whose sum is σ = 47093354225280. Its totient is φ = 9114529513728.

The previous prime is 21267600978061. The next prime is 21267600978079. The reversal of 21267600978064 is 46087900676212.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21267600978061) 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, 5036757 + ... + 8240395.

It is an arithmetic number, because the mean of its divisors is an integer number (1177333855632).

Almost surely, 2^{21267600978064} is an apocalyptic number.

It is an amenable number.

21267600978064 is an abundant number, since it is smaller than the sum of its proper divisors (25825753247216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21267600978064 is a wasteful number, since it uses less digits than its factorization.

21267600978064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3262927 (or 3262921 counting only the distinct ones).

The product of its (nonzero) digits is 12192768, while the sum is 58.

The spelling of 21267600978064 in words is "twenty-one trillion, two hundred sixty-seven billion, six hundred million, nine hundred seventy-eight thousand, sixty-four".