21546737 has 2 divisors, whose sum is σ = 21546738. Its totient is φ = 21546736.

The previous prime is 21546719. The next prime is 21546751. The reversal of 21546737 is 73764512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11806096 + 9740641 = 3436^2 + 3121^2 .

It is a cyclic number.

It is not a de Polignac number, because 21546737 - 2²⁴ = 4769521 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21546697 and 21546706.

It is not a weakly prime, because it can be changed into another prime (21546787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10773368 + 10773369.

It is an arithmetic number, because the mean of its divisors is an integer number (10773369).

Almost surely, 2^21546737 is an apocalyptic number.

It is an amenable number.

21546737 is a deficient number, since it is larger than the sum of its proper divisors (1).

21546737 is an equidigital number, since it uses as much as digits as its factorization.

21546737 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35280, while the sum is 35.

The square root of 21546737 is about 4641.8462921557. The cubic root of 21546737 is about 278.2662296150.

The spelling of 21546737 in words is "twenty-one million, five hundred forty-six thousand, seven hundred thirty-seven".