1971553 has 2 divisors, whose sum is σ = 1971554. Its totient is φ = 1971552.

The previous prime is 1971539. The next prime is 1971577. The reversal of 1971553 is 3551791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1817104 + 154449 = 1348^2 + 393^2 .

It is a cyclic number.

It is not a de Polignac number, because 1971553 - 2⁵ = 1971521 is a prime.

1971553 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1971503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985776 + 985777.

It is an arithmetic number, because the mean of its divisors is an integer number (985777).

2^1971553 is an apocalyptic number.

It is an amenable number.

1971553 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971553 is an equidigital number, since it uses as much as digits as its factorization.

1971553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4725, while the sum is 31.

The square root of 1971553 is about 1404.1200091160. The cubic root of 1971553 is about 125.3919006934.

The spelling of 1971553 in words is "one million, nine hundred seventy-one thousand, five hundred fifty-three".