70531681 has 4 divisors (see below), whose sum is σ = 76943664. Its totient is φ = 64119700.

The previous prime is 70531673. The next prime is 70531687. The reversal of 70531681 is 18613507.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18613507 = 11 ⋅1692137.

It is a cyclic number.

It is not a de Polignac number, because 70531681 - 2³ = 70531673 is a prime.

It is a super-2 number, since 2×70531681² = 9949436049371522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (70531687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3205975 + ... + 3205996.

It is an arithmetic number, because the mean of its divisors is an integer number (19235916).

Almost surely, 2^70531681 is an apocalyptic number.

It is an amenable number.

70531681 is a deficient number, since it is larger than the sum of its proper divisors (6411983).

70531681 is a wasteful number, since it uses less digits than its factorization.

70531681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6411982.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 70531681 is about 8398.3141760713. The cubic root of 70531681 is about 413.1693321936.

The spelling of 70531681 in words is "seventy million, five hundred thirty-one thousand, six hundred eighty-one".