1021221660 has 48 divisors (see below), whose sum is σ = 2958026400. Its totient is φ = 262934784.

The previous prime is 1021221653. The next prime is 1021221673. The reversal of 1021221660 is 661221201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 291715 + ... + 295194.

It is an arithmetic number, because the mean of its divisors is an integer number (61625550).

Almost surely, 2^1021221660 is an apocalyptic number.

1021221660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021221660 is an abundant number, since it is smaller than the sum of its proper divisors (1936804740).

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

1021221660 is a wasteful number, since it uses less digits than its factorization.

1021221660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 586950 (or 586948 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 1021221660 is about 31956.5589511762. The cubic root of 1021221660 is about 1007.0244285359.

Adding to 1021221660 its reverse (661221201), we get a palindrome (1682442861).

The spelling of 1021221660 in words is "one billion, twenty-one million, two hundred twenty-one thousand, six hundred sixty".