70667721 has 10 divisors (see below), whose sum is σ = 105565482. Its totient is φ = 47111760.

The previous prime is 70667719. The next prime is 70667749. The reversal of 70667721 is 12776607.

It can be written as a sum of positive squares in only one way, i.e., 66194496 + 4473225 = 8136^2 + 2115^2 .

It is not a de Polignac number, because 70667721 - 2¹ = 70667719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (70667711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 436140 + ... + 436301.

Almost surely, 2^70667721 is an apocalyptic number.

It is an amenable number.

70667721 is a deficient number, since it is larger than the sum of its proper divisors (34897761).

70667721 is an equidigital number, since it uses as much as digits as its factorization.

70667721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 872453 (or 872444 counting only the distinct ones).

The product of its (nonzero) digits is 24696, while the sum is 36.

The square root of 70667721 is about 8406.4095189326. The cubic root of 70667721 is about 413.4347989859.

The spelling of 70667721 in words is "seventy million, six hundred sixty-seven thousand, seven hundred twenty-one".