21323075737 has 2 divisors, whose sum is σ = 21323075738. Its totient is φ = 21323075736.

The previous prime is 21323075723. The next prime is 21323075747. The reversal of 21323075737 is 73757032312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21136507456 + 186568281 = 145384^2 + 13659^2 .

It is a cyclic number.

It is not a de Polignac number, because 21323075737 - 2¹⁵ = 21323042969 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21323075737.

It is not a weakly prime, because it can be changed into another prime (21323075747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661537868 + 10661537869.

It is an arithmetic number, because the mean of its divisors is an integer number (10661537869).

Almost surely, 2^21323075737 is an apocalyptic number.

It is an amenable number.

21323075737 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323075737 is an equidigital number, since it uses as much as digits as its factorization.

21323075737 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 185220, while the sum is 40.

The spelling of 21323075737 in words is "twenty-one billion, three hundred twenty-three million, seventy-five thousand, seven hundred thirty-seven".