1951941891 has 4 divisors (see below), whose sum is σ = 2602589192. Its totient is φ = 1301294592.

The previous prime is 1951941883. The next prime is 1951941923. The reversal of 1951941891 is 1981491591.

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

It is not a de Polignac number, because 1951941891 - 2³ = 1951941883 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 1951941891.

It is not an unprimeable number, because it can be changed into a prime (1951941821) 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, 325323646 + ... + 325323651.

It is an arithmetic number, because the mean of its divisors is an integer number (650647298).

Almost surely, 2^1951941891 is an apocalyptic number.

1951941891 is a deficient number, since it is larger than the sum of its proper divisors (650647301).

1951941891 is an equidigital number, since it uses as much as digits as its factorization.

1951941891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650647300.

The product of its digits is 116640, while the sum is 48.

The square root of 1951941891 is about 44180.7864461465. The cubic root of 1951941891 is about 1249.7475524329.

The spelling of 1951941891 in words is "one billion, nine hundred fifty-one million, nine hundred forty-one thousand, eight hundred ninety-one".