1021660 has 24 divisors (see below), whose sum is σ = 2239776. Its totient is φ = 390720.

The previous prime is 1021651. The next prime is 1021661. The reversal of 1021660 is 661201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 651 + ... + 1570.

It is an arithmetic number, because the mean of its divisors is an integer number (93324).

2^1021660 is an apocalyptic number.

1021660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021660 is an abundant number, since it is smaller than the sum of its proper divisors (1218116).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1021660 is a wasteful number, since it uses less digits than its factorization.

1021660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2253 (or 2251 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1021660 is about 1010.7719821997. The cubic root of 1021660 is about 100.7168489962.

Adding to 1021660 its reverse (661201), we get a palindrome (1682861).

It can be divided in two parts, 1021 and 660, that added together give a square (1681 = 41²).

The spelling of 1021660 in words is "one million, twenty-one thousand, six hundred sixty".