251321401 has 2 divisors, whose sum is σ = 251321402. Its totient is φ = 251321400.

The previous prime is 251321383. The next prime is 251321449. The reversal of 251321401 is 104123152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 205893801 + 45427600 = 14349^2 + 6740^2 .

It is a cyclic number.

It is not a de Polignac number, because 251321401 - 2¹⁵ = 251288633 is a prime.

It is not a weakly prime, because it can be changed into another prime (251321491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125660700 + 125660701.

It is an arithmetic number, because the mean of its divisors is an integer number (125660701).

Almost surely, 2^251321401 is an apocalyptic number.

It is an amenable number.

251321401 is a deficient number, since it is larger than the sum of its proper divisors (1).

251321401 is an equidigital number, since it uses as much as digits as its factorization.

251321401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 251321401 is about 15853.1195983630. The cubic root of 251321401 is about 631.0684824496.

Adding to 251321401 its reverse (104123152), we get a palindrome (355444553).

The spelling of 251321401 in words is "two hundred fifty-one million, three hundred twenty-one thousand, four hundred one".