61690440 has 96 divisors (see below), whose sum is σ = 212293440. Its totient is φ = 14048640.

The previous prime is 61690379. The next prime is 61690471. The reversal of 61690440 is 4409616.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 61690398 and 61690407.

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, 227505 + ... + 227775.

It is an arithmetic number, because the mean of its divisors is an integer number (2211390).

Almost surely, 2^61690440 is an apocalyptic number.

61690440 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 61690440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106146720).

61690440 is an abundant number, since it is smaller than the sum of its proper divisors (150603000).

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

61690440 is a wasteful number, since it uses less digits than its factorization.

61690440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 61690440 is about 7854.3261964347. The cubic root of 61690440 is about 395.1293492951.

The spelling of 61690440 in words is "sixty-one million, six hundred ninety thousand, four hundred forty".