1955781491 has 8 divisors (see below), whose sum is σ = 1966485264. Its totient is φ = 1945104480.

The previous prime is 1955781481. The next prime is 1955781493. The reversal of 1955781491 is 1941875591.

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 1955781491 - 2¹⁰ = 1955780467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1955781493) 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, 149681 + ... + 162221.

It is an arithmetic number, because the mean of its divisors is an integer number (245810658).

Almost surely, 2^1955781491 is an apocalyptic number.

1955781491 is a deficient number, since it is larger than the sum of its proper divisors (10703773).

1955781491 is a wasteful number, since it uses less digits than its factorization.

1955781491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13381.

The product of its digits is 453600, while the sum is 50.

The square root of 1955781491 is about 44224.2183763603. The cubic root of 1955781491 is about 1250.5664613385.

The spelling of 1955781491 in words is "one billion, nine hundred fifty-five million, seven hundred eighty-one thousand, four hundred ninety-one".