1645161340 has 48 divisors (see below), whose sum is σ = 3615246432. Its totient is φ = 628183296.

The previous prime is 1645161317. The next prime is 1645161347. The reversal of 1645161340 is 431615461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645161347) 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, 18247 + ... + 60193.

It is an arithmetic number, because the mean of its divisors is an integer number (75317634).

Almost surely, 2^1645161340 is an apocalyptic number.

1645161340 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 1645161340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1807623216).

1645161340 is an abundant number, since it is smaller than the sum of its proper divisors (1970085092).

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

1645161340 is a wasteful number, since it uses less digits than its factorization.

1645161340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42046 (or 42044 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 1645161340 is about 40560.5885065786. The cubic root of 1645161340 is about 1180.5095328927.

The spelling of 1645161340 in words is "one billion, six hundred forty-five million, one hundred sixty-one thousand, three hundred forty".