21021211982 has 8 divisors (see below), whose sum is σ = 33191387400. Its totient is φ = 9957416184.

The previous prime is 21021211961. The next prime is 21021211987. The reversal of 21021211982 is 28911212012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021211987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 276594857 + ... + 276594932.

It is an arithmetic number, because the mean of its divisors is an integer number (4148923425).

Almost surely, 2^21021211982 is an apocalyptic number.

21021211982 is a deficient number, since it is larger than the sum of its proper divisors (12170175418).

21021211982 is a wasteful number, since it uses less digits than its factorization.

21021211982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553189810.

The product of its (nonzero) digits is 1152, while the sum is 29.

Adding to 21021211982 its reverse (28911212012), we get a palindrome (49932423994).

The spelling of 21021211982 in words is "twenty-one billion, twenty-one million, two hundred eleven thousand, nine hundred eighty-two".