21212201211990 has 32 divisors (see below), whose sum is σ = 52093219723776. Its totient is φ = 5525038454880.

The previous prime is 21212201211989. The next prime is 21212201212009. The reversal of 21212201211990 is 9911210221212.

It is a congruent 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, 8221782126 + ... + 8221784705.

It is an arithmetic number, because the mean of its divisors is an integer number (1627913116368).

Almost surely, 2^{21212201211990} is an apocalyptic number.

21212201211990 is an abundant number, since it is smaller than the sum of its proper divisors (30881018511786).

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

21212201211990 is a wasteful number, since it uses less digits than its factorization.

21212201211990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16443566884.

The product of its (nonzero) digits is 2592, while the sum is 33.

The spelling of 21212201211990 in words is "twenty-one trillion, two hundred twelve billion, two hundred one million, two hundred eleven thousand, nine hundred ninety".