70713781 has 4 divisors (see below), whose sum is σ = 70731052. Its totient is φ = 70696512.

The previous prime is 70713757. The next prime is 70713787. The reversal of 70713781 is 18731707.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18731707 = 3547 ⋅5281.

It can be written as a sum of positive squares in 2 ways, for example, as 2387025 + 68326756 = 1545^2 + 8266^2 .

It is a cyclic number.

It is not a de Polignac number, because 70713781 - 2⁵ = 70713749 is a prime.

It is a super-2 number, since 2×70713781² = 10000877646631922, 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 (70713787) 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, 1375 + ... + 11971.

It is an arithmetic number, because the mean of its divisors is an integer number (17682763).

Almost surely, 2^70713781 is an apocalyptic number.

It is an amenable number.

70713781 is a deficient number, since it is larger than the sum of its proper divisors (17271).

70713781 is a wasteful number, since it uses less digits than its factorization.

70713781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17270.

The product of its (nonzero) digits is 8232, while the sum is 34.

The square root of 70713781 is about 8409.1486489418. The cubic root of 70713781 is about 413.5246026983.

The spelling of 70713781 in words is "seventy million, seven hundred thirteen thousand, seven hundred eighty-one".