1221653004 has 144 divisors (see below), whose sum is σ = 3515145984. Its totient is φ = 326726400.

The previous prime is 1221652973. The next prime is 1221653011. The reversal of 1221653004 is 4003561221.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 511894 + ... + 514274.

It is an arithmetic number, because the mean of its divisors is an integer number (24410736).

Almost surely, 2^1221653004 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221653004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1757572992).

1221653004 is an abundant number, since it is smaller than the sum of its proper divisors (2293492980).

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

1221653004 is a wasteful number, since it uses less digits than its factorization.

1221653004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2448 (or 2433 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 1221653004 is about 34952.1530667282. The cubic root of 1221653004 is about 1069.0121035895.

The spelling of 1221653004 in words is "one billion, two hundred twenty-one million, six hundred fifty-three thousand, four".