251145021011 has 4 divisors (see below), whose sum is σ = 251150058072. Its totient is φ = 251139983952.

The previous prime is 251145020977. The next prime is 251145021037. The reversal of 251145021011 is 110120541152.

It is a happy number.

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 251145021011 - 2⁶ = 251145020947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251145021511) 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, 2442986 + ... + 2543711.

It is an arithmetic number, because the mean of its divisors is an integer number (62787514518).

Almost surely, 2^251145021011 is an apocalyptic number.

251145021011 is a deficient number, since it is larger than the sum of its proper divisors (5037061).

251145021011 is an equidigital number, since it uses as much as digits as its factorization.

251145021011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5037060.

The product of its (nonzero) digits is 400, while the sum is 23.

Adding to 251145021011 its reverse (110120541152), we get a palindrome (361265562163).

The spelling of 251145021011 in words is "two hundred fifty-one billion, one hundred forty-five million, twenty-one thousand, eleven".