61988940 has 144 divisors (see below), whose sum is σ = 206388000. Its totient is φ = 14966784.

The previous prime is 61988939. The next prime is 61988957. The reversal of 61988940 is 4988916.

Added to its reverse (4988916) it gives a square (66977856 = 8184²).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 137836 + ... + 138284.

It is an arithmetic number, because the mean of its divisors is an integer number (1433250).

Almost surely, 2^61988940 is an apocalyptic number.

61988940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61988940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103194000).

61988940 is an abundant number, since it is smaller than the sum of its proper divisors (144399060).

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

61988940 is a wasteful number, since it uses less digits than its factorization.

61988940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536 (or 531 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 61988940 is about 7873.3055319859. The cubic root of 61988940 is about 395.7656250087.

Adding to 61988940 its reverse (4988916), we get a square (66977856 = 8184²).

The spelling of 61988940 in words is "sixty-one million, nine hundred eighty-eight thousand, nine hundred forty".