1641644040 has 64 divisors (see below), whose sum is σ = 4944188160. Its totient is φ = 436060160.

The previous prime is 1641644033. The next prime is 1641644047. The reversal of 1641644040 is 404461461.

It is an interprime number because it is at equal distance from previous prime (1641644033) and next prime (1641644047).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1641643989 and 1641644007.

It is not an unprimeable number, because it can be changed into a prime (1641644047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4225 + ... + 57455.

It is an arithmetic number, because the mean of its divisors is an integer number (77252940).

Almost surely, 2^1641644040 is an apocalyptic number.

1641644040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1641644040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2472094080).

1641644040 is an abundant number, since it is smaller than the sum of its proper divisors (3302544120).

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

1641644040 is a wasteful number, since it uses less digits than its factorization.

1641644040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53502 (or 53498 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 1641644040 is about 40517.2067151723. The cubic root of 1641644040 is about 1179.6676359733.

The spelling of 1641644040 in words is "one billion, six hundred forty-one million, six hundred forty-four thousand, forty".