61955640 has 96 divisors (see below), whose sum is σ = 203271120. Its totient is φ = 16364544.

The previous prime is 61955603. The next prime is 61955651. The reversal of 61955640 is 4655916.

61955640 is a `hidden beast` number, since 6 + 1 + 9 + 5 + 5 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 61955595 and 61955604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39919 + ... + 41441.

Almost surely, 2^61955640 is an apocalyptic number.

61955640 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 61955640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101635560).

61955640 is an abundant number, since it is smaller than the sum of its proper divisors (141315480).

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

61955640 is a wasteful number, since it uses less digits than its factorization.

61955640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1653 (or 1646 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 61955640 is about 7871.1905071596. The cubic root of 61955640 is about 395.6947448597.

The spelling of 61955640 in words is "sixty-one million, nine hundred fifty-five thousand, six hundred forty".