61811860 has 24 divisors (see below), whose sum is σ = 141605856. Its totient is φ = 22476960.

The previous prime is 61811839. The next prime is 61811903. The reversal of 61811860 is 6811816.

61811860 = 1033² + 1034² + ... + 1087².

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 140262 + ... + 140701.

It is an arithmetic number, because the mean of its divisors is an integer number (5900244).

Almost surely, 2^61811860 is an apocalyptic number.

It is an amenable number.

61811860 is an abundant number, since it is smaller than the sum of its proper divisors (79793996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61811860 is a wasteful number, since it uses less digits than its factorization.

61811860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280983 (or 280981 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 61811860 is about 7862.0518950208. The cubic root of 61811860 is about 395.3884124708.

The spelling of 61811860 in words is "sixty-one million, eight hundred eleven thousand, eight hundred sixty".