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12720978 = 2322330727
BaseRepresentation
bin110000100001…
…101101010010
3212221021220100
4300201231102
511224032403
61132353230
7213061254
oct60415522
925837810
1012720978
1171a9506
124315816
13283520a
141991cd4
1511b42a3
hexc21b52

12720978 has 24 divisors (see below), whose sum is σ = 28761408. Its totient is φ = 4055832.

The previous prime is 12720977. The next prime is 12720997. The reversal of 12720978 is 87902721.

It is not an unprimeable number, because it can be changed into a prime (12720971) 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, 14950 + ... + 15777.

It is an arithmetic number, because the mean of its divisors is an integer number (1198392).

Almost surely, 212720978 is an apocalyptic number.

12720978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

12720978 is an abundant number, since it is smaller than the sum of its proper divisors (16040430).

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

12720978 is a wasteful number, since it uses less digits than its factorization.

12720978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30758 (or 30755 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 12720978 is about 3566.6480061817. The cubic root of 12720978 is about 233.4390464299.

The spelling of 12720978 in words is "twelve million, seven hundred twenty thousand, nine hundred seventy-eight".