1240215251 has 4 divisors (see below), whose sum is σ = 1352962104. Its totient is φ = 1127468400.

The previous prime is 1240215241. The next prime is 1240215257. The reversal of 1240215251 is 1525120421.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1240215251 - 2⁶ = 1240215187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1240215257) 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 3 ways as a sum of consecutive naturals, for example, 56373410 + ... + 56373431.

It is an arithmetic number, because the mean of its divisors is an integer number (338240526).

Almost surely, 2^1240215251 is an apocalyptic number.

1240215251 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1240215251 is a deficient number, since it is larger than the sum of its proper divisors (112746853).

1240215251 is a wasteful number, since it uses less digits than its factorization.

1240215251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112746852.

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 1240215251 is about 35216.6899495112. The cubic root of 1240215251 is about 1074.3992319430.

Adding to 1240215251 its reverse (1525120421), we get a palindrome (2765335672).

The spelling of 1240215251 in words is "one billion, two hundred forty million, two hundred fifteen thousand, two hundred fifty-one".