400020256651 has 2 divisors, whose sum is σ = 400020256652. Its totient is φ = 400020256650.

The previous prime is 400020256613. The next prime is 400020256717. The reversal of 400020256651 is 156652020004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 400020256651 - 2⁷ = 400020256523 is a prime.

It is a super-2 number, since 2×400020256651² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (400020253651) 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, 200010128325 + 200010128326.

It is an arithmetic number, because the mean of its divisors is an integer number (200010128326).

Almost surely, 2^400020256651 is an apocalyptic number.

400020256651 is a deficient number, since it is larger than the sum of its proper divisors (1).

400020256651 is an equidigital number, since it uses as much as digits as its factorization.

400020256651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14400, while the sum is 31.

Adding to 400020256651 its reverse (156652020004), we get a palindrome (556672276655).

The spelling of 400020256651 in words is "four hundred billion, twenty million, two hundred fifty-six thousand, six hundred fifty-one".