1221402992 has 20 divisors (see below), whose sum is σ = 2491019880. Its totient is φ = 578559168.

The previous prime is 1221402991. The next prime is 1221403021. The reversal of 1221402992 is 2992041221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221402991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2008583 + ... + 2009190.

It is an arithmetic number, because the mean of its divisors is an integer number (124550994).

Almost surely, 2^1221402992 is an apocalyptic number.

It is an amenable number.

1221402992 is an abundant number, since it is smaller than the sum of its proper divisors (1269616888).

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

1221402992 is a wasteful number, since it uses less digits than its factorization.

1221402992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4017800 (or 4017794 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 1221402992 is about 34948.5763944685. The cubic root of 1221402992 is about 1068.9391739640.

The spelling of 1221402992 in words is "one billion, two hundred twenty-one million, four hundred two thousand, nine hundred ninety-two".