61100091 has 54 divisors (see below), whose sum is σ = 102249420. Its totient is φ = 35133696.

The previous prime is 61100089. The next prime is 61100093. The reversal of 61100091 is 19000116.

It is an interprime number because it is at equal distance from previous prime (61100089) and next prime (61100093).

It is not a de Polignac number, because 61100091 - 2¹ = 61100089 is a prime.

It is a super-2 number, since 2×61100091² = 7466442240416562, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (61100093) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 439500 + ... + 439638.

Almost surely, 2^61100091 is an apocalyptic number.

61100091 is a deficient number, since it is larger than the sum of its proper divisors (41149329).

61100091 is a wasteful number, since it uses less digits than its factorization.

61100091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 18.

The square root of 61100091 is about 7816.6547192517. The cubic root of 61100091 is about 393.8649055424.

The spelling of 61100091 in words is "sixty-one million, one hundred thousand, ninety-one".