81377090 has 16 divisors (see below), whose sum is σ = 146900088. Its totient is φ = 32457216.

The previous prime is 81377081. The next prime is 81377117. The reversal of 81377090 is 9077318.

It can be written as a sum of positive squares in 4 ways, for example, as 70677649 + 10699441 = 8407^2 + 3271^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81377090.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7997 + ... + 15056.

Almost surely, 2^81377090 is an apocalyptic number.

81377090 is a deficient number, since it is larger than the sum of its proper divisors (65522998).

81377090 is a wasteful number, since it uses less digits than its factorization.

81377090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23413.

The product of its (nonzero) digits is 10584, while the sum is 35.

The square root of 81377090 is about 9020.9251188556. The cubic root of 81377090 is about 433.3452613416.

The spelling of 81377090 in words is "eighty-one million, three hundred seventy-seven thousand, ninety".