420837691 has 2 divisors, whose sum is σ = 420837692. Its totient is φ = 420837690.

The previous prime is 420837643. The next prime is 420837733. The reversal of 420837691 is 196738024.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 420837691 - 2¹⁹ = 420313403 is a prime.

It is a super-2 number, since 2×420837691² = 354208724332422962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (420837611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210418845 + 210418846.

It is an arithmetic number, because the mean of its divisors is an integer number (210418846).

Almost surely, 2^420837691 is an apocalyptic number.

420837691 is a deficient number, since it is larger than the sum of its proper divisors (1).

420837691 is an equidigital number, since it uses as much as digits as its factorization.

420837691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 420837691 is about 20514.3289190751. The cubic root of 420837691 is about 749.3847938702.

The spelling of 420837691 in words is "four hundred twenty million, eight hundred thirty-seven thousand, six hundred ninety-one".