61638126 has 48 divisors (see below), whose sum is σ = 137894400. Its totient is φ = 18348880.

The previous prime is 61638119. The next prime is 61638127. The reversal of 61638126 is 62183616.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61638127) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 42115 + ... + 43553.

It is an arithmetic number, because the mean of its divisors is an integer number (2872800).

Almost surely, 2^61638126 is an apocalyptic number.

61638126 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 61638126, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68947200).

61638126 is an abundant number, since it is smaller than the sum of its proper divisors (76256274).

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

61638126 is a wasteful number, since it uses less digits than its factorization.

61638126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1525 (or 1514 counting only the distinct ones).

The product of its digits is 10368, while the sum is 33.

The square root of 61638126 is about 7850.9952235369. The cubic root of 61638126 is about 395.0176267304.

Subtracting 61638126 from its reverse (62183616), we obtain a triangular number (545490 = T₁₀₄₄).

The spelling of 61638126 in words is "sixty-one million, six hundred thirty-eight thousand, one hundred twenty-six".