1229985729 has 160 divisors (see below), whose sum is σ = 2378956800. Its totient is φ = 617258880.

The previous prime is 1229985721. The next prime is 1229985737. The reversal of 1229985729 is 9275899221.

It is an interprime number because it is at equal distance from previous prime (1229985721) and next prime (1229985737).

It is not a de Polignac number, because 1229985729 - 2³ = 1229985721 is a prime.

It is a super-2 number, since 2×1229985729² = 3025729787087322882, which contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

Its product of digits (1632960) is a multiple of the sum of its prime divisors (216).

It is not an unprimeable number, because it can be changed into a prime (1229985721) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 9684864 + ... + 9684990.

It is an arithmetic number, because the mean of its divisors is an integer number (14868480).

Almost surely, 2^1229985729 is an apocalyptic number.

1229985729 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1229985729 is a deficient number, since it is larger than the sum of its proper divisors (1148971071).

1229985729 is a wasteful number, since it uses less digits than its factorization.

1229985729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 216 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 54.

The square root of 1229985729 is about 35071.1523762764. The cubic root of 1229985729 is about 1071.4371258974.

The spelling of 1229985729 in words is "one billion, two hundred twenty-nine million, nine hundred eighty-five thousand, seven hundred twenty-nine".