70561520021 has 2 divisors, whose sum is σ = 70561520022. Its totient is φ = 70561520020.

The previous prime is 70561519997. The next prime is 70561520023. The reversal of 70561520021 is 12002516507.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70338465796 + 223054225 = 265214^2 + 14935^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-70561520021 is a prime.

Together with 70561520023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70561520023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35280760010 + 35280760011.

It is an arithmetic number, because the mean of its divisors is an integer number (35280760011).

Almost surely, 2^70561520021 is an apocalyptic number.

It is an amenable number.

70561520021 is a deficient number, since it is larger than the sum of its proper divisors (1).

70561520021 is an equidigital number, since it uses as much as digits as its factorization.

70561520021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4200, while the sum is 29.

The spelling of 70561520021 in words is "seventy billion, five hundred sixty-one million, five hundred twenty thousand, twenty-one".