74021640 has 128 divisors (see below), whose sum is σ = 276894720. Its totient is φ = 15379200.

The previous prime is 74021617. The next prime is 74021653. The reversal of 74021640 is 4612047.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 74021640.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5235 + ... + 13245.

It is an arithmetic number, because the mean of its divisors is an integer number (2163240).

Almost surely, 2^74021640 is an apocalyptic number.

74021640 is a gapful number since it is divisible by the number (70) 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 74021640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138447360).

74021640 is an abundant number, since it is smaller than the sum of its proper divisors (202873080).

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

74021640 is a wasteful number, since it uses less digits than its factorization.

74021640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8043 (or 8039 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 74021640 is about 8603.5829745519. The cubic root of 74021640 is about 419.8745657170.

Adding to 74021640 its reverse (4612047), we get a palindrome (78633687).

The spelling of 74021640 in words is "seventy-four million, twenty-one thousand, six hundred forty".