643449740999131 has 16 divisors (see below), whose sum is σ = 715196768693760. Its totient is φ = 573911539549920.

The previous prime is 643449740999113. The next prime is 643449740999167. The reversal of 643449740999131 is 131999047944346.

It is not a de Polignac number, because 643449740999131 - 2⁷ = 643449740999003 is a prime.

It is a super-2 number, since 2×643449740999131² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643449740999111) 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, 51617566 + ... + 62859148.

It is an arithmetic number, because the mean of its divisors is an integer number (44699798043360).

Almost surely, 2^{643449740999131} is an apocalyptic number.

643449740999131 is a deficient number, since it is larger than the sum of its proper divisors (71747027694629).

643449740999131 is a wasteful number, since it uses less digits than its factorization.

643449740999131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11339826.

The product of its (nonzero) digits is 634894848, while the sum is 73.

The spelling of 643449740999131 in words is "six hundred forty-three trillion, four hundred forty-nine billion, seven hundred forty million, nine hundred ninety-nine thousand, one hundred thirty-one".