61881220 has 12 divisors (see below), whose sum is σ = 129950604. Its totient is φ = 24752480.

The previous prime is 61881217. The next prime is 61881223. The reversal of 61881220 is 2218816.

It is an interprime number because it is at equal distance from previous prime (61881217) and next prime (61881223).

It can be written as a sum of positive squares in 2 ways, for example, as 9144576 + 52736644 = 3024^2 + 7262^2 .

It is not an unprimeable number, because it can be changed into a prime (61881223) 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, 1547011 + ... + 1547050.

It is an arithmetic number, because the mean of its divisors is an integer number (10829217).

Almost surely, 2^61881220 is an apocalyptic number.

It is an amenable number.

61881220 is an abundant number, since it is smaller than the sum of its proper divisors (68069384).

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

61881220 is a wasteful number, since it uses less digits than its factorization.

61881220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3094070 (or 3094068 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 61881220 is about 7866.4617204942. The cubic root of 61881220 is about 395.5362475788.

The spelling of 61881220 in words is "sixty-one million, eight hundred eighty-one thousand, two hundred twenty".