1221220019970 has 112 divisors (see below), whose sum is σ = 3296370436920. Its totient is φ = 325600964352.

The previous prime is 1221220019969. The next prime is 1221220020029. The reversal of 1221220019970 is 799100221221.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 322009716681 + 899210303289 = 567459^2 + 948267^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 55225276 + ... + 55247384.

Almost surely, 2^{1221220019970} is an apocalyptic number.

1221220019970 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221220019970, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1648185218460).

1221220019970 is an abundant number, since it is smaller than the sum of its proper divisors (2075150416950).

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

1221220019970 is an equidigital number, since it uses as much as digits as its factorization.

1221220019970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29711 (or 29696 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The spelling of 1221220019970 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, nineteen thousand, nine hundred seventy".