6435981 has 6 divisors (see below), whose sum is σ = 9296430. Its totient is φ = 4290648.

The previous prime is 6435973. The next prime is 6435983. The reversal of 6435981 is 1895346.

6435981 is a `hidden beast` number, since 64 + 3 + 598 + 1 = 666.

6435981 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 4447881 + 1988100 = 2109^2 + 1410^2 .

It is not a de Polignac number, because 6435981 - 2³ = 6435973 is a prime.

It is a super-2 number, since 2×6435981² = 82843702864722, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6435983) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 357546 + ... + 357563.

It is an arithmetic number, because the mean of its divisors is an integer number (1549405).

Almost surely, 2^6435981 is an apocalyptic number.

It is an amenable number.

6435981 is a deficient number, since it is larger than the sum of its proper divisors (2860449).

6435981 is a wasteful number, since it uses less digits than its factorization.

6435981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715115 (or 715112 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 6435981 is about 2536.9235305779. The cubic root of 6435981 is about 186.0108387718.

The spelling of 6435981 in words is "six million, four hundred thirty-five thousand, nine hundred eighty-one".