6401557 has 2 divisors, whose sum is σ = 6401558. Its totient is φ = 6401556.

The previous prime is 6401543. The next prime is 6401569. The reversal of 6401557 is 7551046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4866436 + 1535121 = 2206^2 + 1239^2 .

It is a cyclic number.

It is not a de Polignac number, because 6401557 - 2¹¹ = 6399509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6401587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3200778 + 3200779.

It is an arithmetic number, because the mean of its divisors is an integer number (3200779).

Almost surely, 2^6401557 is an apocalyptic number.

It is an amenable number.

6401557 is a deficient number, since it is larger than the sum of its proper divisors (1).

6401557 is an equidigital number, since it uses as much as digits as its factorization.

6401557 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 28.

The square root of 6401557 is about 2530.1298385656. The cubic root of 6401557 is about 185.6786082775.

It can be divided in two parts, 640 and 1557, that added together give a cube (2197 = 13³).

The spelling of 6401557 in words is "six million, four hundred one thousand, five hundred fifty-seven".