400120021013 has 2 divisors, whose sum is σ = 400120021014. Its totient is φ = 400120021012.

The previous prime is 400120020967. The next prime is 400120021057. The reversal of 400120021013 is 310120021004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 330644550289 + 69475470724 = 575017^2 + 263582^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400120021013 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400120021073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200060010506 + 200060010507.

It is an arithmetic number, because the mean of its divisors is an integer number (200060010507).

Almost surely, 2^400120021013 is an apocalyptic number.

It is an amenable number.

400120021013 is a deficient number, since it is larger than the sum of its proper divisors (1).

400120021013 is an equidigital number, since it uses as much as digits as its factorization.

400120021013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 400120021013 its reverse (310120021004), we get a palindrome (710240042017).

Subtracting from 400120021013 its reverse (310120021004), we obtain a palindrome (90000000009).

The spelling of 400120021013 in words is "four hundred billion, one hundred twenty million, twenty-one thousand, thirteen".