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388977940 = 225131496069
BaseRepresentation
bin10111001011110…
…101010100010100
31000002221010102101
4113023311110110
51244034243230
6102333051444
712432154321
oct2713652424
91002833371
10388977940
1118a62797a
12aa326b84
1362782780
1439935b48
1524237aca
hex172f5514

388977940 has 24 divisors (see below), whose sum is σ = 879689160. Its totient is φ = 143622528.

The previous prime is 388977913. The next prime is 388977949. The reversal of 388977940 is 49779883.

It can be written as a sum of positive squares in 4 ways, for example, as 12152196 + 376825744 = 3486^2 + 19412^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (388977949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 747775 + ... + 748294.

It is an arithmetic number, because the mean of its divisors is an integer number (36653715).

Almost surely, 2388977940 is an apocalyptic number.

It is an amenable number.

388977940 is an abundant number, since it is smaller than the sum of its proper divisors (490711220).

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

388977940 is a wasteful number, since it uses less digits than its factorization.

388977940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1496091 (or 1496089 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 55.

The square root of 388977940 is about 19722.5236721876. The cubic root of 388977940 is about 729.9755668309.

The spelling of 388977940 in words is "three hundred eighty-eight million, nine hundred seventy-seven thousand, nine hundred forty".

Divisors: 1 2 4 5 10 13 20 26 52 65 130 260 1496069 2992138 5984276 7480345 14960690 19448897 29921380 38897794 77795588 97244485 194488970 388977940