29921617890 has 288 divisors, whose sum is σ = 86605593984. Its totient is φ = 7430952960.

The previous prime is 29921617889. The next prime is 29921617961. The reversal of 29921617890 is 9871612992.

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

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 96210835 + ... + 96211145.

It is an arithmetic number, because the mean of its divisors is an integer number (300713868).

Almost surely, 2^29921617890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 29921617890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43302796992).

29921617890 is an abundant number, since it is smaller than the sum of its proper divisors (56683976094).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

29921617890 is a wasteful number, since it uses less digits than its factorization.

29921617890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 504 (or 475 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 54.

The spelling of 29921617890 in words is "twenty-nine billion, nine hundred twenty-one million, six hundred seventeen thousand, eight hundred ninety".