29781990 has 96 divisors (see below), whose sum is σ = 90732096. Its totient is φ = 6635520.

The previous prime is 29781989. The next prime is 29782013. The reversal of 29781990 is 9918792.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25254 + ... + 26406.

It is an arithmetic number, because the mean of its divisors is an integer number (945126).

Almost surely, 2^29781990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 29781990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45366048).

29781990 is an abundant number, since it is smaller than the sum of its proper divisors (60950106).

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

29781990 is a wasteful number, since it uses less digits than its factorization.

29781990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1214 (or 1211 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 29781990 is about 5457.2877879034. The cubic root of 29781990 is about 309.9687446810.

The spelling of 29781990 in words is "twenty-nine million, seven hundred eighty-one thousand, nine hundred ninety".