77623840 has 72 divisors (see below), whose sum is σ = 213348492. Its totient is φ = 26611200.

The previous prime is 77623831. The next prime is 77623849. The reversal of 77623840 is 4832677.

It is an interprime number because it is at equal distance from previous prime (77623831) and next prime (77623849).

It can be written as a sum of positive squares in 2 ways, for example, as 73891216 + 3732624 = 8596^2 + 1932^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 77623840.

It is not an unprimeable number, because it can be changed into a prime (77623849) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2890 + ... + 12790.

Almost surely, 2^77623840 is an apocalyptic number.

77623840 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 77623840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106674246).

77623840 is an abundant number, since it is smaller than the sum of its proper divisors (135724652).

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

77623840 is a wasteful number, since it uses less digits than its factorization.

77623840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9930 (or 9915 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 37.

The square root of 77623840 is about 8810.4392626021. The cubic root of 77623840 is about 426.5779220810.

The spelling of 77623840 in words is "seventy-seven million, six hundred twenty-three thousand, eight hundred forty".