691744451 has 2 divisors, whose sum is σ = 691744452. Its totient is φ = 691744450.

The previous prime is 691744387. The next prime is 691744463. The reversal of 691744451 is 154447196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691744451 - 2⁶ = 691744387 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 691744399 and 691744408.

It is not a weakly prime, because it can be changed into another prime (691744351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345872225 + 345872226.

It is an arithmetic number, because the mean of its divisors is an integer number (345872226).

Almost surely, 2^691744451 is an apocalyptic number.

691744451 is a deficient number, since it is larger than the sum of its proper divisors (1).

691744451 is an equidigital number, since it uses as much as digits as its factorization.

691744451 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 41.

The square root of 691744451 is about 26301.0351697419. The cubic root of 691744451 is about 884.3996485882.

The spelling of 691744451 in words is "six hundred ninety-one million, seven hundred forty-four thousand, four hundred fifty-one".