1221021012 has 12 divisors (see below), whose sum is σ = 2849049056. Its totient is φ = 407007000.

The previous prime is 1221021007. The next prime is 1221021059. The reversal of 1221021012 is 2101201221.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Harshad number since it is a multiple of its sum of digits (12), and also a Moran number because the ratio is a prime number: 101751751 = 1221021012 / (1 + 2 + 2 + 1 + 0 + 2 + 1 + 0 + 1 + 2).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50875864 + ... + 50875887.

Almost surely, 2^1221021012 is an apocalyptic number.

1221021012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221021012 is an abundant number, since it is smaller than the sum of its proper divisors (1628028044).

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

1221021012 is a wasteful number, since it uses less digits than its factorization.

1221021012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101751758 (or 101751756 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1221021012 is about 34943.1110807266. Note that the first 3 decimals coincide. The cubic root of 1221021012 is about 1068.8277294583.

Adding to 1221021012 its reverse (2101201221), we get a palindrome (3322222233).

The spelling of 1221021012 in words is "one billion, two hundred twenty-one million, twenty-one thousand, twelve".