1921679967 has 4 divisors (see below), whose sum is σ = 2562239960. Its totient is φ = 1281119976.

The previous prime is 1921679953. The next prime is 1921680001. The reversal of 1921679967 is 7699761291.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7699761291 = 3 ⋅2566587097.

It is not a de Polignac number, because 1921679967 - 2¹⁹ = 1921155679 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 (1921679927) 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, 320279992 + ... + 320279997.

It is an arithmetic number, because the mean of its divisors is an integer number (640559990).

Almost surely, 2^1921679967 is an apocalyptic number.

1921679967 is a deficient number, since it is larger than the sum of its proper divisors (640559993).

1921679967 is an equidigital number, since it uses as much as digits as its factorization.

1921679967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640559992.

The product of its digits is 2571912, while the sum is 57.

The square root of 1921679967 is about 43836.9703218642. The cubic root of 1921679967 is about 1243.2554000431.

The spelling of 1921679967 in words is "one billion, nine hundred twenty-one million, six hundred seventy-nine thousand, nine hundred sixty-seven".