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131920081 = 806916349
BaseRepresentation
bin1111101110011…
…11000011010001
3100012020020022221
413313033003101
5232232420311
621031301041
73161205436
oct767170321
9305206287
10131920081
1168513567
123821a781
132143b727
141373db8d
15b8ac671
hex7dcf0d1

131920081 has 4 divisors (see below), whose sum is σ = 131944500. Its totient is φ = 131895664.

The previous prime is 131920067. The next prime is 131920091. The reversal of 131920081 is 180029131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6838225 + 125081856 = 2615^2 + 11184^2 .

It is a cyclic number.

It is not a de Polignac number, because 131920081 - 29 = 131919569 is a prime.

It is a super-2 number, since 2×1319200812 = 34805815542093122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131920091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106 + ... + 16243.

It is an arithmetic number, because the mean of its divisors is an integer number (32986125).

Almost surely, 2131920081 is an apocalyptic number.

It is an amenable number.

131920081 is a deficient number, since it is larger than the sum of its proper divisors (24419).

131920081 is an equidigital number, since it uses as much as digits as its factorization.

131920081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24418.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 131920081 is about 11485.6467384297. The cubic root of 131920081 is about 509.0615588860.

The spelling of 131920081 in words is "one hundred thirty-one million, nine hundred twenty thousand, eighty-one".

Divisors: 1 8069 16349 131920081