1252406221 has 4 divisors (see below), whose sum is σ = 1366261344. Its totient is φ = 1138551100.

The previous prime is 1252406159. The next prime is 1252406249. The reversal of 1252406221 is 1226042521.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1252406221 - 2⁹ = 1252405709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1252406021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56927545 + ... + 56927566.

It is an arithmetic number, because the mean of its divisors is an integer number (341565336).

Almost surely, 2^1252406221 is an apocalyptic number.

1252406221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1252406221 is a deficient number, since it is larger than the sum of its proper divisors (113855123).

1252406221 is a wasteful number, since it uses less digits than its factorization.

1252406221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113855122.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 1252406221 is about 35389.3518024843. The cubic root of 1252406221 is about 1077.9081081036.

Adding to 1252406221 its reverse (1226042521), we get a palindrome (2478448742).

The spelling of 1252406221 in words is "one billion, two hundred fifty-two million, four hundred six thousand, two hundred twenty-one".