840720738 has 64 divisors (see below), whose sum is σ = 1986026112. Its totient is φ = 233902080.

The previous prime is 840720731. The next prime is 840720743. The reversal of 840720738 is 837027048.

It is a super-2 number, since 2×840720738² = 1413622718606529288, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 840720696 and 840720705.

It is not an unprimeable number, because it can be changed into a prime (840720731) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 163056 + ... + 168132.

It is an arithmetic number, because the mean of its divisors is an integer number (31031658).

Almost surely, 2^840720738 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 840720738, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (993013056).

840720738 is an abundant number, since it is smaller than the sum of its proper divisors (1145305374).

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

840720738 is a wasteful number, since it uses less digits than its factorization.

840720738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5299.

The product of its (nonzero) digits is 75264, while the sum is 39.

The square root of 840720738 is about 28995.1847381595. The cubic root of 840720738 is about 943.8085777538.

The spelling of 840720738 in words is "eight hundred forty million, seven hundred twenty thousand, seven hundred thirty-eight".