6405961 has 3 divisors (see below), whose sum is σ = 6408493. Its totient is φ = 6403430.

The previous prime is 6405943. The next prime is 6405979. The reversal of 6405961 is 1695046.

The square root of 6405961 is 2531.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (6405943) and next prime (6405979).

It is not a de Polignac number, because 6405961 - 2⁵ = 6405929 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (6405901) 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 in 2 ways as a sum of consecutive naturals, for example, 1266 + ... + 3796.

Almost surely, 2^6405961 is an apocalyptic number.

6405961 is the 2531-st square number.

6405961 is the 1266-th centered octagonal number.

It is an amenable number.

6405961 is a deficient number, since it is larger than the sum of its proper divisors (2532).

6405961 is an frugal number, since it uses more digits than its factorization.

6405961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5062 (or 2531 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The cubic root of 6405961 is about 185.7211781888.

Subtracting from 6405961 its reverse (1695046), we obtain a triangular number (4710915 = T₃₀₆₉).

The spelling of 6405961 in words is "six million, four hundred five thousand, nine hundred sixty-one".