1229100021 has 32 divisors (see below), whose sum is σ = 1843459200. Its totient is φ = 809308800.

The previous prime is 1229099999. The next prime is 1229100053. The reversal of 1229100021 is 1200019221.

It is not a de Polignac number, because 1229100021 - 2¹⁵ = 1229067253 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1229099967 and 1229100003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1229100721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 846346 + ... + 847796.

It is an arithmetic number, because the mean of its divisors is an integer number (57608100).

Almost surely, 2^1229100021 is an apocalyptic number.

It is an amenable number.

1229100021 is a deficient number, since it is larger than the sum of its proper divisors (614359179).

1229100021 is a wasteful number, since it uses less digits than its factorization.

1229100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1826 (or 1820 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 1229100021 is about 35058.5228011678. The cubic root of 1229100021 is about 1071.1798848882.

Adding to 1229100021 its reverse (1200019221), we get a palindrome (2429119242).

The spelling of 1229100021 in words is "one billion, two hundred twenty-nine million, one hundred thousand, twenty-one".