1200121011 has 24 divisors (see below), whose sum is σ = 1837806464. Its totient is φ = 753338880.

The previous prime is 1200121009. The next prime is 1200121019. The reversal of 1200121011 is 1101210021.

It is a happy number.

It is not a de Polignac number, because 1200121011 - 2¹ = 1200121009 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1200120984 and 1200121002.

It is not an unprimeable number, because it can be changed into a prime (1200121019) 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, 47806 + ... + 68451.

Almost surely, 2^1200121011 is an apocalyptic number.

1200121011 is a deficient number, since it is larger than the sum of its proper divisors (637685453).

1200121011 is a wasteful number, since it uses less digits than its factorization.

1200121011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116331 (or 116328 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 1200121011 is about 34642.7627506814. The cubic root of 1200121011 is about 1062.6942883642.

Adding to 1200121011 its reverse (1101210021), we get a palindrome (2301331032).

The spelling of 1200121011 in words is "one billion, two hundred million, one hundred twenty-one thousand, eleven".