70251221 has 2 divisors, whose sum is σ = 70251222. Its totient is φ = 70251220.

The previous prime is 70251217. The next prime is 70251281. The reversal of 70251221 is 12215207.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64224196 + 6027025 = 8014^2 + 2455^2 .

It is a cyclic number.

It is not a de Polignac number, because 70251221 - 2² = 70251217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 70251193 and 70251202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70251281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35125610 + 35125611.

It is an arithmetic number, because the mean of its divisors is an integer number (35125611).

Almost surely, 2^70251221 is an apocalyptic number.

It is an amenable number.

70251221 is a deficient number, since it is larger than the sum of its proper divisors (1).

70251221 is an equidigital number, since it uses as much as digits as its factorization.

70251221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 70251221 is about 8381.6001455569. The cubic root of 70251221 is about 412.6209667878.

Adding to 70251221 its reverse (12215207), we get a palindrome (82466428).

The spelling of 70251221 in words is "seventy million, two hundred fifty-one thousand, two hundred twenty-one".