70251521 has 2 divisors, whose sum is σ = 70251522. Its totient is φ = 70251520.

The previous prime is 70251509. The next prime is 70251523. The reversal of 70251521 is 12515207.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54538225 + 15713296 = 7385^2 + 3964^2 .

It is a cyclic number.

It is not a de Polignac number, because 70251521 - 2⁶ = 70251457 is a prime.

Together with 70251523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (70251523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35125760 + 35125761.

It is an arithmetic number, because the mean of its divisors is an integer number (35125761).

Almost surely, 2^70251521 is an apocalyptic number.

It is an amenable number.

70251521 is a deficient number, since it is larger than the sum of its proper divisors (1).

70251521 is an equidigital number, since it uses as much as digits as its factorization.

70251521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 700, while the sum is 23.

The square root of 70251521 is about 8381.6180418819. The cubic root of 70251521 is about 412.6215541375.

Adding to 70251521 its reverse (12515207), we get a palindrome (82766728).

The spelling of 70251521 in words is "seventy million, two hundred fifty-one thousand, five hundred twenty-one".