61866121 has 4 divisors (see below), whose sum is σ = 63304912. Its totient is φ = 60427332.

The previous prime is 61866107. The next prime is 61866131. The reversal of 61866121 is 12166816.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61866121 - 2¹⁷ = 61735049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61866131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 719331 + ... + 719416.

It is an arithmetic number, because the mean of its divisors is an integer number (15826228).

Almost surely, 2^61866121 is an apocalyptic number.

It is an amenable number.

61866121 is a deficient number, since it is larger than the sum of its proper divisors (1438791).

61866121 is a wasteful number, since it uses less digits than its factorization.

61866121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1438790.

The product of its digits is 3456, while the sum is 31.

The square root of 61866121 is about 7865.5019547388. The cubic root of 61866121 is about 395.5040747182.

The spelling of 61866121 in words is "sixty-one million, eight hundred sixty-six thousand, one hundred twenty-one".