1212021019978 has 16 divisors (see below), whose sum is σ = 1897122741696. Its totient is φ = 579648060640.

The previous prime is 1212021019973. The next prime is 1212021019997. The reversal of 1212021019978 is 8799101202121.

It is a happy number.

It is a super-2 number, since 2×1212021019978² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1212021019973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1719993 + ... + 2320003.

It is an arithmetic number, because the mean of its divisors is an integer number (118570171356).

Almost surely, 2^{1212021019978} is an apocalyptic number.

1212021019978 is a deficient number, since it is larger than the sum of its proper divisors (685101721718).

1212021019978 is a wasteful number, since it uses less digits than its factorization.

1212021019978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643949.

The product of its (nonzero) digits is 36288, while the sum is 43.

The spelling of 1212021019978 in words is "one trillion, two hundred twelve billion, twenty-one million, nineteen thousand, nine hundred seventy-eight".