252243640 has 64 divisors (see below), whose sum is σ = 626693760. Its totient is φ = 90606720.

The previous prime is 252243631. The next prime is 252243643. The reversal of 252243640 is 46342252.

It is a junction number, because it is equal to n+sod(n) for n = 252243599 and 252243608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (252243643) 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, 33067 + ... + 39973.

It is an arithmetic number, because the mean of its divisors is an integer number (9792090).

Almost surely, 2^252243640 is an apocalyptic number.

252243640 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 252243640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (313346880).

252243640 is an abundant number, since it is smaller than the sum of its proper divisors (374450120).

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

252243640 is a wasteful number, since it uses less digits than its factorization.

252243640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7012 (or 7008 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 28.

The square root of 252243640 is about 15882.1799511276. The cubic root of 252243640 is about 631.8394547608.

Adding to 252243640 its reverse (46342252), we get a palindrome (298585892).

The spelling of 252243640 in words is "two hundred fifty-two million, two hundred forty-three thousand, six hundred forty".