619661 has 4 divisors (see below), whose sum is σ = 708192. Its totient is φ = 531132.

The previous prime is 619657. The next prime is 619669. The reversal of 619661 is 166916.

619661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 619661 - 2² = 619657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (619669) 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, 44255 + ... + 44268.

It is an arithmetic number, because the mean of its divisors is an integer number (177048).

2⁶¹⁹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

619661 is a deficient number, since it is larger than the sum of its proper divisors (88531).

619661 is an equidigital number, since it uses as much as digits as its factorization.

619661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88530.

The product of its digits is 1944, while the sum is 29.

The square root of 619661 is about 787.1854927525. The cubic root of 619661 is about 85.2546458197.

The spelling of 619661 in words is "six hundred nineteen thousand, six hundred sixty-one".