19677421 has 2 divisors, whose sum is σ = 19677422. Its totient is φ = 19677420.

The previous prime is 19677419. The next prime is 19677433. The reversal of 19677421 is 12477691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11492100 + 8185321 = 3390^2 + 2861^2 .

It is a cyclic number.

It is not a de Polignac number, because 19677421 - 2¹ = 19677419 is a prime.

It is a super-2 number, since 2×19677421² = 774401794422482, which contains 22 as substring.

Together with 19677419, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19677401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9838710 + 9838711.

It is an arithmetic number, because the mean of its divisors is an integer number (9838711).

Almost surely, 2^19677421 is an apocalyptic number.

It is an amenable number.

19677421 is a deficient number, since it is larger than the sum of its proper divisors (1).

19677421 is an equidigital number, since it uses as much as digits as its factorization.

19677421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 37.

The square root of 19677421 is about 4435.9239172916. The cubic root of 19677421 is about 269.9744877586.

The spelling of 19677421 in words is "nineteen million, six hundred seventy-seven thousand, four hundred twenty-one".