1912921 has 2 divisors, whose sum is σ = 1912922. Its totient is φ = 1912920.

The previous prime is 1912919. The next prime is 1912943. The reversal of 1912921 is 1292191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1625625 + 287296 = 1275^2 + 536^2 .

It is a cyclic number.

It is not a de Polignac number, because 1912921 - 2¹ = 1912919 is a prime.

Together with 1912919, it forms a pair of twin primes.

It is equal to p₁₄₂₉₂₇ and since 1912921 and 142927 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (1912951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 956460 + 956461.

It is an arithmetic number, because the mean of its divisors is an integer number (956461).

2^1912921 is an apocalyptic number.

It is an amenable number.

1912921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1912921 is an equidigital number, since it uses as much as digits as its factorization.

1912921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 324, while the sum is 25.

The square root of 1912921 is about 1383.0838730894. The cubic root of 1912921 is about 124.1363614363.

The spelling of 1912921 in words is "one million, nine hundred twelve thousand, nine hundred twenty-one".