21002119966 has 16 divisors (see below), whose sum is σ = 31645329408. Its totient is φ = 10453708800.

The previous prime is 21002119951. The next prime is 21002119967. The reversal of 21002119966 is 66991120012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002119967) 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, 1720926 + ... + 1733086.

It is an arithmetic number, because the mean of its divisors is an integer number (1977833088).

Almost surely, 2^21002119966 is an apocalyptic number.

21002119966 is a deficient number, since it is larger than the sum of its proper divisors (10643209442).

21002119966 is a wasteful number, since it uses less digits than its factorization.

21002119966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15987.

The product of its (nonzero) digits is 11664, while the sum is 37.

Adding to 21002119966 its reverse (66991120012), we get a palindrome (87993239978).

The spelling of 21002119966 in words is "twenty-one billion, two million, one hundred nineteen thousand, nine hundred sixty-six".