2145731220 has 72 divisors (see below), whose sum is σ = 6517320264. Its totient is φ = 571438848.

The previous prime is 2145731219. The next prime is 2145731221. The reversal of 2145731220 is 221375412.

It is an interprime number because it is at equal distance from previous prime (2145731219) and next prime (2145731221).

It can be written as a sum of positive squares in 4 ways, for example, as 72386064 + 2073345156 = 8508^2 + 45534^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145731221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 135982 + ... + 150938.

It is an arithmetic number, because the mean of its divisors is an integer number (90518337).

Almost surely, 2^2145731220 is an apocalyptic number.

2145731220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2145731220 is an abundant number, since it is smaller than the sum of its proper divisors (4371589044).

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

2145731220 is a wasteful number, since it uses less digits than its factorization.

2145731220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15769 (or 15764 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 2145731220 is about 46322.0381675936. The cubic root of 2145731220 is about 1289.8081200091.

The spelling of 2145731220 in words is "two billion, one hundred forty-five million, seven hundred thirty-one thousand, two hundred twenty".