2145205040 has 80 divisors (see below), whose sum is σ = 5469935616. Its totient is φ = 775929600.

The previous prime is 2145205039. The next prime is 2145205043. The reversal of 2145205040 is 405025412.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 2145204997 and 2145205015.

It is not an unprimeable number, because it can be changed into a prime (2145205043) 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, 161699 + ... + 174461.

Almost surely, 2^2145205040 is an apocalyptic number.

2145205040 is a gapful number since it is divisible by the number (20) 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 2145205040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2734967808).

2145205040 is an abundant number, since it is smaller than the sum of its proper divisors (3324730576).

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

2145205040 is a wasteful number, since it uses less digits than its factorization.

2145205040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12978 (or 12972 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 2145205040 is about 46316.3582333499. The cubic root of 2145205040 is about 1289.7026817149.

The spelling of 2145205040 in words is "two billion, one hundred forty-five million, two hundred five thousand, forty".