70240021 has 2 divisors, whose sum is σ = 70240022. Its totient is φ = 70240020.

The previous prime is 70240007. The next prime is 70240057. The reversal of 70240021 is 12004207.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57380625 + 12859396 = 7575^2 + 3586^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-70240021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 70239977 and 70240004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70240721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35120010 + 35120011.

It is an arithmetic number, because the mean of its divisors is an integer number (35120011).

Almost surely, 2^70240021 is an apocalyptic number.

It is an amenable number.

70240021 is a deficient number, since it is larger than the sum of its proper divisors (1).

70240021 is an equidigital number, since it uses as much as digits as its factorization.

70240021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 70240021 is about 8380.9319887468. The cubic root of 70240021 is about 412.5990378667.

Adding to 70240021 its reverse (12004207), we get a palindrome (82244228).

The spelling of 70240021 in words is "seventy million, two hundred forty thousand, twenty-one".