1971905 has 16 divisors (see below), whose sum is σ = 2661120. Its totient is φ = 1391808.

The previous prime is 1971901. The next prime is 1971911. The reversal of 1971905 is 5091791.

It is a cyclic number.

It is not a de Polignac number, because 1971905 - 2² = 1971901 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1971901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 836 + ... + 2154.

It is an arithmetic number, because the mean of its divisors is an integer number (166320).

2^1971905 is an apocalyptic number.

It is an amenable number.

1971905 is a deficient number, since it is larger than the sum of its proper divisors (689215).

1971905 is a wasteful number, since it uses less digits than its factorization.

1971905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1360.

The product of its (nonzero) digits is 2835, while the sum is 32.

The square root of 1971905 is about 1404.2453489330. The cubic root of 1971905 is about 125.3993627165.

The spelling of 1971905 in words is "one million, nine hundred seventy-one thousand, nine hundred five".