619978 has 4 divisors (see below), whose sum is σ = 929970. Its totient is φ = 309988.

The previous prime is 619967. The next prime is 619979. The reversal of 619978 is 879916.

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

It can be written as a sum of positive squares in only one way, i.e., 613089 + 6889 = 783^2 + 83^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 619978.

It is not an unprimeable number, because it can be changed into a prime (619979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154993 + ... + 154996.

2⁶¹⁹⁹⁷⁸ is an apocalyptic number.

619978 is a deficient number, since it is larger than the sum of its proper divisors (309992).

619978 is a wasteful number, since it uses less digits than its factorization.

619978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309991.

The product of its digits is 27216, while the sum is 40.

The square root of 619978 is about 787.3868172633. The cubic root of 619978 is about 85.2691812487.

The spelling of 619978 in words is "six hundred nineteen thousand, nine hundred seventy-eight".