619891 has 4 divisors (see below), whose sum is σ = 622512. Its totient is φ = 617272.

The previous prime is 619867. The next prime is 619897. The reversal of 619891 is 198916.

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

It is a cyclic number.

It is not a de Polignac number, because 619891 - 2⁷ = 619763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (619897) 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, 916 + ... + 1441.

It is an arithmetic number, because the mean of its divisors is an integer number (155628).

2⁶¹⁹⁸⁹¹ is an apocalyptic number.

619891 is a deficient number, since it is larger than the sum of its proper divisors (2621).

619891 is a wasteful number, since it uses less digits than its factorization.

619891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2620.

The product of its digits is 3888, while the sum is 34.

The square root of 619891 is about 787.3315692896. The cubic root of 619891 is about 85.2651925235.

It can be divided in two parts, 61 and 9891, that multiplied together give a triangular number (603351 = T₁₀₉₈).

The spelling of 619891 in words is "six hundred nineteen thousand, eight hundred ninety-one".