1221636948 has 48 divisors (see below), whose sum is σ = 3370039680. Its totient is φ = 337002624.

The previous prime is 1221636947. The next prime is 1221636979. The reversal of 1221636948 is 8496361221.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221636947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 248311 + ... + 253182.

It is an arithmetic number, because the mean of its divisors is an integer number (70209160).

Almost surely, 2^1221636948 is an apocalyptic number.

It is an amenable number.

1221636948 is an abundant number, since it is smaller than the sum of its proper divisors (2148402732).

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

1221636948 is a wasteful number, since it uses less digits than its factorization.

1221636948 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 501536 (or 501534 counting only the distinct ones).

The product of its digits is 124416, while the sum is 42.

The square root of 1221636948 is about 34951.9233805523. The cubic root of 1221636948 is about 1069.0074202811.

The spelling of 1221636948 in words is "one billion, two hundred twenty-one million, six hundred thirty-six thousand, nine hundred forty-eight".