151721640 has 384 divisors, whose sum is σ = 610675200. Its totient is φ = 33384960.

The previous prime is 151721623. The next prime is 151721681. The reversal of 151721640 is 46127151.

It is a happy number.

151721640 is a `hidden beast` number, since 1 + 5 + 17 + 2 + 1 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2487210 + ... + 2487270.

It is an arithmetic number, because the mean of its divisors is an integer number (1590300).

Almost surely, 2^151721640 is an apocalyptic number.

151721640 is a gapful number since it is divisible by the number (10) 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 151721640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (305337600).

151721640 is an abundant number, since it is smaller than the sum of its proper divisors (458953560).

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

151721640 is a wasteful number, since it uses less digits than its factorization.

151721640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 151721640 is about 12317.5338440777. The cubic root of 151721640 is about 533.3543516022.

Adding to 151721640 its reverse (46127151), we get a palindrome (197848791).

The spelling of 151721640 in words is "one hundred fifty-one million, seven hundred twenty-one thousand, six hundred forty".