1961558091079 has 6 divisors (see below), whose sum is σ = 1985476065776. Its totient is φ = 1937924854260.

The previous prime is 1961558091023. The next prime is 1961558091083. The reversal of 1961558091079 is 9701908551691.

It is not a de Polignac number, because 1961558091079 - 2¹⁷ = 1961557960007 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1961558092079) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 142361967 + ... + 142375744.

Almost surely, 2^{1961558091079} is an apocalyptic number.

1961558091079 is a deficient number, since it is larger than the sum of its proper divisors (23917974697).

1961558091079 is an frugal number, since it uses more digits than its factorization.

1961558091079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284737877 (or 284737794 counting only the distinct ones).

The product of its (nonzero) digits is 6123600, while the sum is 61.

The spelling of 1961558091079 in words is "one trillion, nine hundred sixty-one billion, five hundred fifty-eight million, ninety-one thousand, seventy-nine".