61781629 has 32 divisors (see below), whose sum is σ = 80720640. Its totient is φ = 45964800.

The previous prime is 61781627. The next prime is 61781633. The reversal of 61781629 is 92618716.

It is not a de Polignac number, because 61781629 - 2¹ = 61781627 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 61781591 and 61781600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61781627) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 107914 + ... + 108484.

It is an arithmetic number, because the mean of its divisors is an integer number (2522520).

Almost surely, 2^61781629 is an apocalyptic number.

It is an amenable number.

61781629 is a deficient number, since it is larger than the sum of its proper divisors (18939011).

61781629 is a wasteful number, since it uses less digits than its factorization.

61781629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661.

The product of its digits is 36288, while the sum is 40.

The square root of 61781629 is about 7860.1290701871. The cubic root of 61781629 is about 395.3239429861.

The spelling of 61781629 in words is "sixty-one million, seven hundred eighty-one thousand, six hundred twenty-nine".