1681394940 has 36 divisors (see below), whose sum is σ = 5100231864. Its totient is φ = 448371936.

The previous prime is 1681394929. The next prime is 1681394947. The reversal of 1681394940 is 494931861.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681394947) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4670362 + ... + 4670721.

Almost surely, 2^1681394940 is an apocalyptic number.

1681394940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1681394940 is an abundant number, since it is smaller than the sum of its proper divisors (3418836924).

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

1681394940 is a wasteful number, since it uses less digits than its factorization.

1681394940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9341098 (or 9341093 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 1681394940 is about 41004.8160586046. The cubic root of 1681394940 is about 1189.1133239138.

The spelling of 1681394940 in words is "one billion, six hundred eighty-one million, three hundred ninety-four thousand, nine hundred forty".