70145981 has 4 divisors (see below), whose sum is σ = 70252764. Its totient is φ = 70039200.

The previous prime is 70145947. The next prime is 70145989. The reversal of 70145981 is 18954107.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 58277956 + 11868025 = 7634^2 + 3445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-70145981 is a prime.

It is a super-3 number, since 3×70145981³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (70145989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52400 + ... + 53721.

It is an arithmetic number, because the mean of its divisors is an integer number (17563191).

Almost surely, 2^70145981 is an apocalyptic number.

It is an amenable number.

70145981 is a deficient number, since it is larger than the sum of its proper divisors (106783).

70145981 is a wasteful number, since it uses less digits than its factorization.

70145981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106782.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 70145981 is about 8375.3197550900. The cubic root of 70145981 is about 412.4148212247.

The spelling of 70145981 in words is "seventy million, one hundred forty-five thousand, nine hundred eighty-one".