400221617 has 2 divisors, whose sum is σ = 400221618. Its totient is φ = 400221616.

The previous prime is 400221611. The next prime is 400221673. The reversal of 400221617 is 716122004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 391406656 + 8814961 = 19784^2 + 2969^2 .

It is a cyclic number.

It is not a de Polignac number, because 400221617 - 2¹⁰ = 400220593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 400221592 and 400221601.

It is not a weakly prime, because it can be changed into another prime (400221611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200110808 + 200110809.

It is an arithmetic number, because the mean of its divisors is an integer number (200110809).

Almost surely, 2^400221617 is an apocalyptic number.

It is an amenable number.

400221617 is a deficient number, since it is larger than the sum of its proper divisors (1).

400221617 is an equidigital number, since it uses as much as digits as its factorization.

400221617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 400221617 is about 20005.5396578048. The cubic root of 400221617 is about 736.9423486070.

The spelling of 400221617 in words is "four hundred million, two hundred twenty-one thousand, six hundred seventeen".