21135747673 has 16 divisors (see below), whose sum is σ = 22550524416. Its totient is φ = 19763307520.

The previous prime is 21135747667. The next prime is 21135747697. The reversal of 21135747673 is 37674753112.

It is a de Polignac number, because none of the positive numbers 2^k-21135747673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21135747643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 941265 + ... + 963457.

It is an arithmetic number, because the mean of its divisors is an integer number (1409407776).

Almost surely, 2^21135747673 is an apocalyptic number.

21135747673 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21135747673 is a deficient number, since it is larger than the sum of its proper divisors (1414776743).

21135747673 is a wasteful number, since it uses less digits than its factorization.

21135747673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23144.

The product of its digits is 740880, while the sum is 46.

The spelling of 21135747673 in words is "twenty-one billion, one hundred thirty-five million, seven hundred forty-seven thousand, six hundred seventy-three".