55690681 has 2 divisors, whose sum is σ = 55690682. Its totient is φ = 55690680.

The previous prime is 55690673. The next prime is 55690699. The reversal of 55690681 is 18609655.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35521600 + 20169081 = 5960^2 + 4491^2 .

It is a cyclic number.

It is not a de Polignac number, because 55690681 - 2³ = 55690673 is a prime.

It is a super-2 number, since 2×55690681² = 6202903900487522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (55690081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27845340 + 27845341.

It is an arithmetic number, because the mean of its divisors is an integer number (27845341).

Almost surely, 2^55690681 is an apocalyptic number.

It is an amenable number.

55690681 is a deficient number, since it is larger than the sum of its proper divisors (1).

55690681 is an equidigital number, since it uses as much as digits as its factorization.

55690681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64800, while the sum is 40.

The square root of 55690681 is about 7462.6189102754. The cubic root of 55690681 is about 381.8805237499.

The spelling of 55690681 in words is "fifty-five million, six hundred ninety thousand, six hundred eighty-one".