70000781 has 16 divisors (see below), whose sum is σ = 76895280. Its totient is φ = 63452160.

The previous prime is 70000771. The next prime is 70000783. The reversal of 70000781 is 18700007.

It can be written as a sum of positive squares in 8 ways, for example, as 17147881 + 52852900 = 4141^2 + 7270^2 .

It is not a de Polignac number, because 70000781 - 2⁶ = 70000717 is a prime.

It is a super-2 number, since 2×70000781² = 9800218681219922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (70000783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68051 + ... + 69071.

It is an arithmetic number, because the mean of its divisors is an integer number (4805955).

Almost surely, 2^70000781 is an apocalyptic number.

It is an amenable number.

70000781 is a deficient number, since it is larger than the sum of its proper divisors (6894499).

70000781 is a wasteful number, since it uses less digits than its factorization.

70000781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1184.

The product of its (nonzero) digits is 392, while the sum is 23.

The square root of 70000781 is about 8366.6469388878. The cubic root of 70000781 is about 412.1300627008.

Adding to 70000781 its reverse (18700007), we get a palindrome (88700788).

The spelling of 70000781 in words is "seventy million, seven hundred eighty-one", and thus it is an aban number.