6406021709965 has 4 divisors (see below), whose sum is σ = 7687226051964. Its totient is φ = 5124817367968.

The previous prime is 6406021709957. The next prime is 6406021709987. The reversal of 6406021709965 is 5699071206046.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4634466033961 + 1771555676004 = 2152781^2 + 1330998^2 .

It is a cyclic number.

It is not a de Polignac number, because 6406021709965 - 2³ = 6406021709957 is a prime.

It is a super-2 number, since 2×6406021709965² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 640602170992 + ... + 640602171001.

It is an arithmetic number, because the mean of its divisors is an integer number (1921806512991).

Almost surely, 2^{6406021709965} is an apocalyptic number.

It is an amenable number.

6406021709965 is a deficient number, since it is larger than the sum of its proper divisors (1281204341999).

6406021709965 is a wasteful number, since it uses less digits than its factorization.

6406021709965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1281204341998.

The product of its (nonzero) digits is 4898880, while the sum is 55.

The spelling of 6406021709965 in words is "six trillion, four hundred six billion, twenty-one million, seven hundred nine thousand, nine hundred sixty-five".