1221929604 has 192 divisors, whose sum is σ = 3958456320. Its totient is φ = 317882880.

The previous prime is 1221929593. The next prime is 1221929623. The reversal of 1221929604 is 4069291221.

1221929604 is a `hidden beast` number, since 1 + 2 + 21 + 9 + 29 + 604 = 666.

It is a super-2 number, since 2×1221929604² = 2986223914263193632, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 396879 + ... + 399945.

It is an arithmetic number, because the mean of its divisors is an integer number (20616960).

Almost surely, 2^1221929604 is an apocalyptic number.

1221929604 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221929604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1979228160).

1221929604 is an abundant number, since it is smaller than the sum of its proper divisors (2736526716).

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

1221929604 is a wasteful number, since it uses less digits than its factorization.

1221929604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3135 (or 3127 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 1221929604 is about 34956.1096805694. The cubic root of 1221929604 is about 1069.0927774616.

The spelling of 1221929604 in words is "one billion, two hundred twenty-one million, nine hundred twenty-nine thousand, six hundred four".