1978193405 has 8 divisors (see below), whose sum is σ = 2374714584. Its totient is φ = 1581966400.

The previous prime is 1978193401. The next prime is 1978193429. The reversal of 1978193405 is 5043918791.

It can be written as a sum of positive squares in 4 ways, for example, as 14462809 + 1963730596 = 3803^2 + 44314^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1978193405 - 2² = 1978193401 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 1978193405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978193401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58466 + ... + 85875.

It is an arithmetic number, because the mean of its divisors is an integer number (296839323).

Almost surely, 2^1978193405 is an apocalyptic number.

It is an amenable number.

1978193405 is a deficient number, since it is larger than the sum of its proper divisors (396521179).

1978193405 is a wasteful number, since it uses less digits than its factorization.

1978193405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147087.

The product of its (nonzero) digits is 272160, while the sum is 47.

The square root of 1978193405 is about 44476.8861882214. The cubic root of 1978193405 is about 1255.3252079128.

The spelling of 1978193405 in words is "one billion, nine hundred seventy-eight million, one hundred ninety-three thousand, four hundred five".