1634841421491 has 4 divisors (see below), whose sum is σ = 2179788561992. Its totient is φ = 1089894280992.

The previous prime is 1634841421439. The next prime is 1634841421523. The reversal of 1634841421491 is 1941241484361.

It is a happy number.

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

It is not a de Polignac number, because 1634841421491 - 2²² = 1634837227187 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1634841421491.

It is not an unprimeable number, because it can be changed into a prime (1634841421091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 272473570246 + ... + 272473570251.

It is an arithmetic number, because the mean of its divisors is an integer number (544947140498).

Almost surely, 2^{1634841421491} is an apocalyptic number.

1634841421491 is a deficient number, since it is larger than the sum of its proper divisors (544947140501).

1634841421491 is an equidigital number, since it uses as much as digits as its factorization.

1634841421491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544947140500.

The product of its digits is 663552, while the sum is 48.

The spelling of 1634841421491 in words is "one trillion, six hundred thirty-four billion, eight hundred forty-one million, four hundred twenty-one thousand, four hundred ninety-one".