1221071016 has 48 divisors (see below), whose sum is σ = 3355430400. Its totient is φ = 370020640.

The previous prime is 1221070931. The next prime is 1221071041. The reversal of 1221071016 is 6101701221.

1221071016 = 2546² + 2547² + ... + 2721².

It is a happy number.

It is a super-2 number, since 2×1221071016² = 2982028852230544512, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221070983 and 1221071001.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 207336 + ... + 213143.

It is an arithmetic number, because the mean of its divisors is an integer number (69904800).

Almost surely, 2^1221071016 is an apocalyptic number.

It is an amenable number.

1221071016 is an abundant number, since it is smaller than the sum of its proper divisors (2134359384).

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

1221071016 is a wasteful number, since it uses less digits than its factorization.

1221071016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420510 (or 420495 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 21.

The square root of 1221071016 is about 34943.8265792400. The cubic root of 1221071016 is about 1068.8423196883.

Adding to 1221071016 its reverse (6101701221), we get a palindrome (7322772237).

The spelling of 1221071016 in words is "one billion, two hundred twenty-one million, seventy-one thousand, sixteen".