29668639 has 32 divisors (see below), whose sum is σ = 40352256. Its totient is φ = 21064320.

The previous prime is 29668627. The next prime is 29668657. The reversal of 29668639 is 93686692.

It is a cyclic number.

It is not a de Polignac number, because 29668639 - 2⁵ = 29668607 is a prime.

It is a super-2 number, since 2×29668639² = 1760456280224642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 29668592 and 29668601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (29668619) 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, 106969 + ... + 107245.

It is an arithmetic number, because the mean of its divisors is an integer number (1261008).

Almost surely, 2^29668639 is an apocalyptic number.

29668639 is a deficient number, since it is larger than the sum of its proper divisors (10683617).

29668639 is a wasteful number, since it uses less digits than its factorization.

29668639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415.

The product of its digits is 839808, while the sum is 49.

The square root of 29668639 is about 5446.8926003732. The cubic root of 29668639 is about 309.5749951150.

The spelling of 29668639 in words is "twenty-nine million, six hundred sixty-eight thousand, six hundred thirty-nine".