61681072 has 40 divisors (see below), whose sum is σ = 126733952. Its totient is φ = 29030400.

The previous prime is 61681043. The next prime is 61681079. The reversal of 61681072 is 27018616.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is not an unprimeable number, because it can be changed into a prime (61681079) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16672 + ... + 20032.

Almost surely, 2^61681072 is an apocalyptic number.

61681072 is a gapful number since it is divisible by the number (62) 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 61681072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63366976).

61681072 is an abundant number, since it is smaller than the sum of its proper divisors (65052880).

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

61681072 is a wasteful number, since it uses less digits than its factorization.

61681072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3437 (or 3431 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 61681072 is about 7853.7298145531. The cubic root of 61681072 is about 395.1093474973.

Adding to 61681072 its reverse (27018616), we get a palindrome (88699688).

The spelling of 61681072 in words is "sixty-one million, six hundred eighty-one thousand, seventy-two".