70897081781 has 4 divisors (see below), whose sum is σ = 70897933632. Its totient is φ = 70896229932.

The previous prime is 70897081769. The next prime is 70897081789. The reversal of 70897081781 is 18718079807.

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: 18718079807 = 7 ⋅2674011401.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-70897081781 is a prime.

It is a super-2 number, since 2×70897081781² (a number of 23 digits) 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 (70897081789) 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, 285695 + ... + 472668.

It is an arithmetic number, because the mean of its divisors is an integer number (17724483408).

Almost surely, 2^70897081781 is an apocalyptic number.

It is an amenable number.

70897081781 is a deficient number, since it is larger than the sum of its proper divisors (851851).

70897081781 is an equidigital number, since it uses as much as digits as its factorization.

70897081781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 851850.

The product of its (nonzero) digits is 1580544, while the sum is 56.

The spelling of 70897081781 in words is "seventy billion, eight hundred ninety-seven million, eighty-one thousand, seven hundred eighty-one".