61661355 has 48 divisors (see below), whose sum is σ = 117494784. Its totient is φ = 27518400.

The previous prime is 61661339. The next prime is 61661357. The reversal of 61661355 is 55316616.

It is not a de Polignac number, because 61661355 - 2⁴ = 61661339 is a prime.

It is a super-3 number, since 3×61661355³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61661357) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 30630 + ... + 32580.

It is an arithmetic number, because the mean of its divisors is an integer number (2447808).

Almost surely, 2^61661355 is an apocalyptic number.

61661355 is a deficient number, since it is larger than the sum of its proper divisors (55833429).

61661355 is a wasteful number, since it uses less digits than its factorization.

61661355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2016 (or 2009 counting only the distinct ones).

The product of its digits is 16200, while the sum is 33.

The square root of 61661355 is about 7852.4744507703. The cubic root of 61661355 is about 395.0672427317.

The spelling of 61661355 in words is "sixty-one million, six hundred sixty-one thousand, three hundred fifty-five".