20211229987 has 16 divisors (see below), whose sum is σ = 21911547168. Its totient is φ = 18531912960.

The previous prime is 20211229949. The next prime is 20211229999. The reversal of 20211229987 is 78992211202.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20211229987 - 2⁷ = 20211229859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20211329987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2967528 + ... + 2974330.

It is an arithmetic number, because the mean of its divisors is an integer number (1369471698).

Almost surely, 2^20211229987 is an apocalyptic number.

20211229987 is a deficient number, since it is larger than the sum of its proper divisors (1700317181).

20211229987 is a wasteful number, since it uses less digits than its factorization.

20211229987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8310.

The product of its (nonzero) digits is 72576, while the sum is 43.

The spelling of 20211229987 in words is "twenty billion, two hundred eleven million, two hundred twenty-nine thousand, nine hundred eighty-seven".