691479427 has 2 divisors, whose sum is σ = 691479428. Its totient is φ = 691479426.

The previous prime is 691479419. The next prime is 691479487. The reversal of 691479427 is 724974196.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 691479427 - 2³ = 691479419 is a prime.

It is not a weakly prime, because it can be changed into another prime (691479487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345739713 + 345739714.

It is an arithmetic number, because the mean of its divisors is an integer number (345739714).

Almost surely, 2^691479427 is an apocalyptic number.

691479427 is a deficient number, since it is larger than the sum of its proper divisors (1).

691479427 is an equidigital number, since it uses as much as digits as its factorization.

691479427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 49.

The square root of 691479427 is about 26295.9964062973. The cubic root of 691479427 is about 884.2866892086.

The spelling of 691479427 in words is "six hundred ninety-one million, four hundred seventy-nine thousand, four hundred twenty-seven".