921407 has 2 divisors, whose sum is σ = 921408. Its totient is φ = 921406.

The previous prime is 921379. The next prime is 921409. The reversal of 921407 is 704129.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-921407 is a prime.

Together with 921409, it forms a pair of twin primes.

It is a Chen prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (921409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460703 + 460704.

It is an arithmetic number, because the mean of its divisors is an integer number (460704).

2⁹²¹⁴⁰⁷ is an apocalyptic number.

921407 is a deficient number, since it is larger than the sum of its proper divisors (1).

921407 is an equidigital number, since it uses as much as digits as its factorization.

921407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 921407 is about 959.8994739034. The cubic root of 921407 is about 97.3084382548.

The spelling of 921407 in words is "nine hundred twenty-one thousand, four hundred seven".