212111019978 has 32 divisors (see below), whose sum is σ = 498386734272. Its totient is φ = 59331753600.

The previous prime is 212111019917. The next prime is 212111020013. The reversal of 212111019978 is 879910111212.

It is a super-2 number, since 2×212111019978² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 123606963 + ... + 123608678.

It is an arithmetic number, because the mean of its divisors is an integer number (15574585446).

Almost surely, 2^212111019978 is an apocalyptic number.

212111019978 is an abundant number, since it is smaller than the sum of its proper divisors (286275714294).

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

212111019978 is a wasteful number, since it uses less digits than its factorization.

212111019978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247215670.

The product of its (nonzero) digits is 18144, while the sum is 42.

The spelling of 212111019978 in words is "two hundred twelve billion, one hundred eleven million, nineteen thousand, nine hundred seventy-eight".