1643997426547 has 8 divisors (see below), whose sum is σ = 1878864917600. Its totient is φ = 1409132614464.

The previous prime is 1643997426521. The next prime is 1643997426559. The reversal of 1643997426547 is 7456247993461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1643997426547 - 2²³ = 1643989037939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643997426587) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 886279 + ... + 2018287.

It is an arithmetic number, because the mean of its divisors is an integer number (234858114700).

Almost surely, 2^{1643997426547} is an apocalyptic number.

1643997426547 is a deficient number, since it is larger than the sum of its proper divisors (234867491053).

1643997426547 is a wasteful number, since it uses less digits than its factorization.

1643997426547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1339485.

The product of its digits is 274337280, while the sum is 67.

The spelling of 1643997426547 in words is "one trillion, six hundred forty-three billion, nine hundred ninety-seven million, four hundred twenty-six thousand, five hundred forty-seven".