643451767161 has 16 divisors (see below), whose sum is σ = 980511135744. Its totient is φ = 367681772304.

The previous prime is 643451767141. The next prime is 643451767163. The reversal of 643451767161 is 161767154346.

It is not a de Polignac number, because 643451767161 - 2⁶ = 643451767097 is a prime.

It is a super-2 number, since 2×643451767161² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (643451767163) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1881390 + ... + 2196936.

It is an arithmetic number, because the mean of its divisors is an integer number (61281945984).

Almost surely, 2^643451767161 is an apocalyptic number.

It is an amenable number.

643451767161 is a deficient number, since it is larger than the sum of its proper divisors (337059368583).

643451767161 is a wasteful number, since it uses less digits than its factorization.

643451767161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412660.

The product of its digits is 2540160, while the sum is 51.

The spelling of 643451767161 in words is "six hundred forty-three billion, four hundred fifty-one million, seven hundred sixty-seven thousand, one hundred sixty-one".