21012301573 has 2 divisors, whose sum is σ = 21012301574. Its totient is φ = 21012301572.

The previous prime is 21012301469. The next prime is 21012301577. The reversal of 21012301573 is 37510321012.

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., 19982084164 + 1030217409 = 141358^2 + 32097^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012301573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012301577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506150786 + 10506150787.

It is an arithmetic number, because the mean of its divisors is an integer number (10506150787).

Almost surely, 2^21012301573 is an apocalyptic number.

It is an amenable number.

21012301573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012301573 is an equidigital number, since it uses as much as digits as its factorization.

21012301573 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 25.

Adding to 21012301573 its reverse (37510321012), we get a palindrome (58522622585).

The spelling of 21012301573 in words is "twenty-one billion, twelve million, three hundred one thousand, five hundred seventy-three".