61645240 has 32 divisors (see below), whose sum is σ = 139423680. Its totient is φ = 24529792.

The previous prime is 61645237. The next prime is 61645261. The reversal of 61645240 is 4254616.

61645240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×61645240² = 7600271229315200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 61645199 and 61645208.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3969 + ... + 11791.

It is an arithmetic number, because the mean of its divisors is an integer number (4356990).

Almost surely, 2^61645240 is an apocalyptic number.

It is an amenable number.

61645240 is an abundant number, since it is smaller than the sum of its proper divisors (77778440).

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

61645240 is a wasteful number, since it uses less digits than its factorization.

61645240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8031 (or 8027 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 61645240 is about 7851.4482740447. The cubic root of 61645240 is about 395.0328232084.

Adding to 61645240 its reverse (4254616), we get a palindrome (65899856).

The spelling of 61645240 in words is "sixty-one million, six hundred forty-five thousand, two hundred forty".