1221201028 has 6 divisors (see below), whose sum is σ = 2137101806. Its totient is φ = 610600512.

The previous prime is 1221201019. The next prime is 1221201083. The reversal of 1221201028 is 8201021221.

It can be written as a sum of positive squares in only one way, i.e., 761870404 + 459330624 = 27602^2 + 21432^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1221200996 and 1221201014.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 152650125 + ... + 152650132.

Almost surely, 2^1221201028 is an apocalyptic number.

It is an amenable number.

1221201028 is a deficient number, since it is larger than the sum of its proper divisors (915900778).

1221201028 is a wasteful number, since it uses less digits than its factorization.

1221201028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305300261 (or 305300259 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 1221201028 is about 34945.6868297076. The cubic root of 1221201028 is about 1068.8802528891.

Adding to 1221201028 its reverse (8201021221), we get a palindrome (9422222249).

The spelling of 1221201028 in words is "one billion, two hundred twenty-one million, two hundred one thousand, twenty-eight".