61621881 has 16 divisors (see below), whose sum is σ = 85669056. Its totient is φ = 39364416.

The previous prime is 61621873. The next prime is 61621891. The reversal of 61621881 is 18812616.

It is not a de Polignac number, because 61621881 - 2³ = 61621873 is a prime.

It is a super-2 number, since 2×61621881² = 7594512435956322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61621801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2331 + ... + 11343.

It is an arithmetic number, because the mean of its divisors is an integer number (5354316).

Almost surely, 2^61621881 is an apocalyptic number.

It is an amenable number.

61621881 is a deficient number, since it is larger than the sum of its proper divisors (24047175).

61621881 is a wasteful number, since it uses less digits than its factorization.

61621881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9112.

The product of its digits is 4608, while the sum is 33.

The square root of 61621881 is about 7849.9605731494. The cubic root of 61621881 is about 394.9829208019.

The spelling of 61621881 in words is "sixty-one million, six hundred twenty-one thousand, eight hundred eighty-one".