694445981 has 2 divisors, whose sum is σ = 694445982. Its totient is φ = 694445980.

The previous prime is 694445963. The next prime is 694445993. The reversal of 694445981 is 189544496.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 419881081 + 274564900 = 20491^2 + 16570^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-694445981 is a prime.

It is a super-2 number, since 2×694445981² = 964510441054104722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (694445581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 347222990 + 347222991.

It is an arithmetic number, because the mean of its divisors is an integer number (347222991).

Almost surely, 2^694445981 is an apocalyptic number.

It is an amenable number.

694445981 is a deficient number, since it is larger than the sum of its proper divisors (1).

694445981 is an equidigital number, since it uses as much as digits as its factorization.

694445981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1244160, while the sum is 50.

The square root of 694445981 is about 26352.3429888122. The cubic root of 694445981 is about 885.5494607853.

It can be divided in two parts, 6944 and 45981, that added together give a palindrome (52925).

The spelling of 694445981 in words is "six hundred ninety-four million, four hundred forty-five thousand, nine hundred eighty-one".