21273065064 has 48 divisors (see below), whose sum is σ = 57916235520. Its totient is φ = 7053891360.

The previous prime is 21273065063. The next prime is 21273065083. The reversal of 21273065064 is 46056037212.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21273065063) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 759702 + ... + 787205.

It is an arithmetic number, because the mean of its divisors is an integer number (1206588240).

Almost surely, 2^21273065064 is an apocalyptic number.

21273065064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21273065064 is an abundant number, since it is smaller than the sum of its proper divisors (36643170456).

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

21273065064 is a wasteful number, since it uses less digits than its factorization.

21273065064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1547110 (or 1547103 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The spelling of 21273065064 in words is "twenty-one billion, two hundred seventy-three million, sixty-five thousand, sixty-four".