1213531251 has 16 divisors (see below), whose sum is σ = 1665856896. Its totient is φ = 785344896.

The previous prime is 1213531223. The next prime is 1213531259. The reversal of 1213531251 is 1521353121.

It is not a de Polignac number, because 1213531251 - 2⁹ = 1213530739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1213531259) 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, 7830 + ... + 49883.

It is an arithmetic number, because the mean of its divisors is an integer number (104116056).

Almost surely, 2^1213531251 is an apocalyptic number.

1213531251 is a deficient number, since it is larger than the sum of its proper divisors (452325645).

1213531251 is a wasteful number, since it uses less digits than its factorization.

1213531251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57922.

The product of its digits is 900, while the sum is 24.

The square root of 1213531251 is about 34835.7754470889. The cubic root of 1213531251 is about 1066.6378440237.

Adding to 1213531251 its reverse (1521353121), we get a palindrome (2734884372).

The spelling of 1213531251 in words is "one billion, two hundred thirteen million, five hundred thirty-one thousand, two hundred fifty-one".