29971331640 has 160 divisors (see below), whose sum is σ = 101405763360. Its totient is φ = 7939296000.

The previous prime is 29971331639. The next prime is 29971331641. The reversal of 29971331640 is 4613317992.

29971331640 is a `hidden beast` number, since 299 + 7 + 1 + 3 + 316 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (29971331639) and next prime (29971331641).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (29971331641) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 458610 + ... + 519870.

It is an arithmetic number, because the mean of its divisors is an integer number (633786021).

Almost surely, 2^29971331640 is an apocalyptic number.

29971331640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 29971331640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50702881680).

29971331640 is an abundant number, since it is smaller than the sum of its proper divisors (71434431720).

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

29971331640 is a wasteful number, since it uses less digits than its factorization.

29971331640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61435 (or 61422 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The spelling of 29971331640 in words is "twenty-nine billion, nine hundred seventy-one million, three hundred thirty-one thousand, six hundred forty".