1978545 has 16 divisors (see below), whose sum is σ = 3352320. Its totient is φ = 993024.

The previous prime is 1978541. The next prime is 1978567. The reversal of 1978545 is 5458791.

1978545 = 323² + 324² + ... + 340².

It is not a de Polignac number, because 1978545 - 2² = 1978541 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1978541) 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, 3625 + ... + 4134.

It is an arithmetic number, because the mean of its divisors is an integer number (209520).

2^1978545 is an apocalyptic number.

1978545 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1978545 is a deficient number, since it is larger than the sum of its proper divisors (1373775).

1978545 is a wasteful number, since it uses less digits than its factorization.

1978545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7784.

The product of its digits is 50400, while the sum is 39.

The square root of 1978545 is about 1406.6076211936. The cubic root of 1978545 is about 125.5399575417.

The spelling of 1978545 in words is "one million, nine hundred seventy-eight thousand, five hundred forty-five".