70777981 has 2 divisors, whose sum is σ = 70777982. Its totient is φ = 70777980.

The previous prime is 70777979. The next prime is 70777997. The reversal of 70777981 is 18977707.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70644025 + 133956 = 8405^2 + 366^2 .

It is a cyclic number.

It is not a de Polignac number, because 70777981 - 2¹ = 70777979 is a prime.

It is a super-2 number, since 2×70777981² = 10019045188872722, which contains 22 as substring.

Together with 70777979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70777901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35388990 + 35388991.

It is an arithmetic number, because the mean of its divisors is an integer number (35388991).

Almost surely, 2^70777981 is an apocalyptic number.

It is an amenable number.

70777981 is a deficient number, since it is larger than the sum of its proper divisors (1).

70777981 is an equidigital number, since it uses as much as digits as its factorization.

70777981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 172872, while the sum is 46.

The square root of 70777981 is about 8412.9650540104. The cubic root of 70777981 is about 413.6497091434.

The spelling of 70777981 in words is "seventy million, seven hundred seventy-seven thousand, nine hundred eighty-one".