1280190091 has 4 divisors (see below), whose sum is σ = 1295614152. Its totient is φ = 1264766032.

The previous prime is 1280190059. The next prime is 1280190127. The reversal of 1280190091 is 1900910821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1900910821 = 29 ⋅65548649.

It is a cyclic number.

It is not a de Polignac number, because 1280190091 - 2⁵ = 1280190059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1280190011) 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, 7711906 + ... + 7712071.

It is an arithmetic number, because the mean of its divisors is an integer number (323903538).

Almost surely, 2^1280190091 is an apocalyptic number.

1280190091 is a deficient number, since it is larger than the sum of its proper divisors (15424061).

1280190091 is an equidigital number, since it uses as much as digits as its factorization.

1280190091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15424060.

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 1280190091 is about 35779.7441438588. The cubic root of 1280190091 is about 1085.8207925566.

The spelling of 1280190091 in words is "one billion, two hundred eighty million, one hundred ninety thousand, ninety-one".