1252440405 has 24 divisors (see below), whose sum is σ = 2298597912. Its totient is φ = 628675584.

The previous prime is 1252440401. The next prime is 1252440451. The reversal of 1252440405 is 5040442521.

1252440405 is a `hidden beast` number, since 1 + 252 + 4 + 4 + 0 + 405 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 376398801 + 876041604 = 19401^2 + 29598^2 .

It is not a de Polignac number, because 1252440405 - 2² = 1252440401 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1252440401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 817824 + ... + 819353.

It is an arithmetic number, because the mean of its divisors is an integer number (95774913).

Almost surely, 2^1252440405 is an apocalyptic number.

1252440405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1252440405 is a deficient number, since it is larger than the sum of its proper divisors (1046157507).

1252440405 is a wasteful number, since it uses less digits than its factorization.

1252440405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1637205 (or 1637202 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 27.

The square root of 1252440405 is about 35389.8347693232. The cubic root of 1252440405 is about 1077.9179150589.

Adding to 1252440405 its reverse (5040442521), we get a palindrome (6292882926).

The spelling of 1252440405 in words is "one billion, two hundred fifty-two million, four hundred forty thousand, four hundred five".