1917961 has 2 divisors, whose sum is σ = 1917962. Its totient is φ = 1917960.

The previous prime is 1917959. The next prime is 1917967. The reversal of 1917961 is 1697191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1742400 + 175561 = 1320^2 + 419^2 .

It is an emirp because it is prime and its reverse (1697191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1917961 - 2¹ = 1917959 is a prime.

Together with 1917959, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1917967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 958980 + 958981.

It is an arithmetic number, because the mean of its divisors is an integer number (958981).

2^1917961 is an apocalyptic number.

It is an amenable number.

1917961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1917961 is an equidigital number, since it uses as much as digits as its factorization.

1917961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3402, while the sum is 34.

The square root of 1917961 is about 1384.9046898614. The cubic root of 1917961 is about 124.2452871050.

The spelling of 1917961 in words is "one million, nine hundred seventeen thousand, nine hundred sixty-one".