1646181940 has 24 divisors (see below), whose sum is σ = 3722904360. Its totient is φ = 607820928.

The previous prime is 1646181923. The next prime is 1646181941. The reversal of 1646181940 is 491816461.

It can be written as a sum of positive squares in 4 ways, for example, as 65642404 + 1580539536 = 8102^2 + 39756^2 .

It is a super-3 number, since 3×1646181940³ (a number of 29 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1646181893 and 1646181902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1646181941) 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, 3165475 + ... + 3165994.

It is an arithmetic number, because the mean of its divisors is an integer number (155121015).

Almost surely, 2^1646181940 is an apocalyptic number.

1646181940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1646181940 is an abundant number, since it is smaller than the sum of its proper divisors (2076722420).

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

1646181940 is a wasteful number, since it uses less digits than its factorization.

1646181940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6331491 (or 6331489 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 1646181940 is about 40573.1677343537. The cubic root of 1646181940 is about 1180.7535979056.

The spelling of 1646181940 in words is "one billion, six hundred forty-six million, one hundred eighty-one thousand, nine hundred forty".