1977561 has 8 divisors (see below), whose sum is σ = 2929760. Its totient is φ = 1318356.

The previous prime is 1977557. The next prime is 1977571. The reversal of 1977561 is 1657791.

1977561 is a `hidden beast` number, since 1 + 97 + 7 + 561 = 666.

It is not a de Polignac number, because 1977561 - 2² = 1977557 is a prime.

It is a Duffinian number.

It is a Curzon number.

1977561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1977541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36595 + ... + 36648.

It is an arithmetic number, because the mean of its divisors is an integer number (366220).

2^1977561 is an apocalyptic number.

It is an amenable number.

1977561 is a deficient number, since it is larger than the sum of its proper divisors (952199).

1977561 is an equidigital number, since it uses as much as digits as its factorization.

1977561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73252 (or 73246 counting only the distinct ones).

The product of its digits is 13230, while the sum is 36.

The square root of 1977561 is about 1406.2577999784. The cubic root of 1977561 is about 125.5191422789.

The spelling of 1977561 in words is "one million, nine hundred seventy-seven thousand, five hundred sixty-one".