1306993021 has 2 divisors, whose sum is σ = 1306993022. Its totient is φ = 1306993020.

The previous prime is 1306993003. The next prime is 1306993027. The reversal of 1306993021 is 1203996031.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1014104025 + 292888996 = 31845^2 + 17114^2 .

It is a cyclic number.

It is not a de Polignac number, because 1306993021 - 2⁵ = 1306992989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1306993027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 653496510 + 653496511.

It is an arithmetic number, because the mean of its divisors is an integer number (653496511).

Almost surely, 2^1306993021 is an apocalyptic number.

It is an amenable number.

1306993021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1306993021 is an equidigital number, since it uses as much as digits as its factorization.

1306993021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8748, while the sum is 34.

The square root of 1306993021 is about 36152.3584431224. The cubic root of 1306993021 is about 1093.3463417940.

The spelling of 1306993021 in words is "one billion, three hundred six million, nine hundred ninety-three thousand, twenty-one".