1978065 has 24 divisors (see below), whose sum is σ = 3467880. Its totient is φ = 1042944.

The previous prime is 1978063. The next prime is 1978087. The reversal of 1978065 is 5608791.

It can be written as a sum of positive squares in 4 ways, for example, as 40401 + 1937664 = 201^2 + 1392^2 .

It is not a de Polignac number, because 1978065 - 2¹ = 1978063 is a prime.

It is a super-2 number, since 2×1978065² = 7825482288450, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978063) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4891 + ... + 5279.

It is an arithmetic number, because the mean of its divisors is an integer number (144495).

2^1978065 is an apocalyptic number.

1978065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1978065 is a deficient number, since it is larger than the sum of its proper divisors (1489815).

1978065 is a wasteful number, since it uses less digits than its factorization.

1978065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The square root of 1978065 is about 1406.4369875682. The cubic root of 1978065 is about 125.5298046173.

The spelling of 1978065 in words is "one million, nine hundred seventy-eight thousand, sixty-five".