55641561 has 32 divisors (see below), whose sum is σ = 81285120. Its totient is φ = 33720576.

The previous prime is 55641533. The next prime is 55641563. The reversal of 55641561 is 16514655.

It is not a de Polignac number, because 55641561 - 2⁹ = 55641049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55641563) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 333100 + ... + 333266.

It is an arithmetic number, because the mean of its divisors is an integer number (2540160).

Almost surely, 2^55641561 is an apocalyptic number.

55641561 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

55641561 is a deficient number, since it is larger than the sum of its proper divisors (25643559).

55641561 is a wasteful number, since it uses less digits than its factorization.

55641561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373.

The product of its digits is 18000, while the sum is 33.

The square root of 55641561 is about 7459.3271144253. The cubic root of 55641561 is about 381.7682159776.

The spelling of 55641561 in words is "fifty-five million, six hundred forty-one thousand, five hundred sixty-one".