1978728419 has 8 divisors (see below), whose sum is σ = 2150062080. Its totient is φ = 1814113800.

The previous prime is 1978728397. The next prime is 1978728421. The reversal of 1978728419 is 9148278791.

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

It is not a de Polignac number, because 1978728419 - 2¹² = 1978724323 is a prime.

It is a super-2 number, since 2×1978728419² = 7830732312316479122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1978728469) 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, 1679147 + ... + 1680324.

It is an arithmetic number, because the mean of its divisors is an integer number (268757760).

Almost surely, 2^1978728419 is an apocalyptic number.

1978728419 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1978728419 is a deficient number, since it is larger than the sum of its proper divisors (171333661).

1978728419 is a wasteful number, since it uses less digits than its factorization.

1978728419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3359521.

The product of its digits is 2032128, while the sum is 56.

The square root of 1978728419 is about 44482.9002988789. The cubic root of 1978728419 is about 1255.4383677317.

The spelling of 1978728419 in words is "one billion, nine hundred seventy-eight million, seven hundred twenty-eight thousand, four hundred nineteen".