1212290820 has 384 divisors, whose sum is σ = 4374720000. Its totient is φ = 276203520.

The previous prime is 1212290813. The next prime is 1212290843. The reversal of 1212290820 is 280922121.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 8136106 + ... + 8136254.

It is an arithmetic number, because the mean of its divisors is an integer number (11392500).

Almost surely, 2^1212290820 is an apocalyptic number.

1212290820 is a gapful number since it is divisible by the number (10) 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 1212290820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2187360000).

1212290820 is an abundant number, since it is smaller than the sum of its proper divisors (3162429180).

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

1212290820 is a wasteful number, since it uses less digits than its factorization.

1212290820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260 (or 252 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1212290820 is about 34817.9669136496. The cubic root of 1212290820 is about 1066.2742929659.

The spelling of 1212290820 in words is "one billion, two hundred twelve million, two hundred ninety thousand, eight hundred twenty".