1681419978 has 64 divisors (see below), whose sum is σ = 4274691840. Its totient is φ = 479908800.

The previous prime is 1681419973. The next prime is 1681419979. The reversal of 1681419978 is 8799141861.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (1681419973) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 520408 + ... + 523628.

It is an arithmetic number, because the mean of its divisors is an integer number (66792060).

Almost surely, 2^1681419978 is an apocalyptic number.

1681419978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1681419978 is an abundant number, since it is smaller than the sum of its proper divisors (2593271862).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1681419978 is a wasteful number, since it uses less digits than its factorization.

1681419978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4620 (or 4614 counting only the distinct ones).

The product of its digits is 870912, while the sum is 54.

The square root of 1681419978 is about 41005.1213630688. The cubic root of 1681419978 is about 1189.1192263286.

The spelling of 1681419978 in words is "one billion, six hundred eighty-one million, four hundred nineteen thousand, nine hundred seventy-eight".