61644631 has 4 divisors (see below), whose sum is σ = 62489152. Its totient is φ = 60800112.

The previous prime is 61644617. The next prime is 61644697. The reversal of 61644631 is 13644616.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61644631 - 2¹¹ = 61642583 is a prime.

It is a super-2 number, since 2×61644631² = 7600121062252322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61644593 and 61644602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61644731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 422151 + ... + 422296.

It is an arithmetic number, because the mean of its divisors is an integer number (15622288).

Almost surely, 2^61644631 is an apocalyptic number.

61644631 is a deficient number, since it is larger than the sum of its proper divisors (844521).

61644631 is an equidigital number, since it uses as much as digits as its factorization.

61644631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844520.

The product of its digits is 10368, while the sum is 31.

The square root of 61644631 is about 7851.4094912952. The cubic root of 61644631 is about 395.0315223468.

The spelling of 61644631 in words is "sixty-one million, six hundred forty-four thousand, six hundred thirty-one".