400061021 has 2 divisors, whose sum is σ = 400061022. Its totient is φ = 400061020.

The previous prime is 400060987. The next prime is 400061023. The reversal of 400061021 is 120160004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 389628121 + 10432900 = 19739^2 + 3230^2 .

It is a cyclic number.

It is not a de Polignac number, because 400061021 - 2⁶ = 400060957 is a prime.

Together with 400061023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 400060987 and 400061005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400061023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200030510 + 200030511.

It is an arithmetic number, because the mean of its divisors is an integer number (200030511).

Almost surely, 2^400061021 is an apocalyptic number.

It is an amenable number.

400061021 is a deficient number, since it is larger than the sum of its proper divisors (1).

400061021 is an equidigital number, since it uses as much as digits as its factorization.

400061021 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.

The square root of 400061021 is about 20001.5254668238. The cubic root of 400061021 is about 736.8437650373.

The spelling of 400061021 in words is "four hundred million, sixty-one thousand, twenty-one".