61545840 has 40 divisors (see below), whose sum is σ = 190792848. Its totient is φ = 16412160.

The previous prime is 61545839. The next prime is 61545863. The reversal of 61545840 is 4854516.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 127981 + ... + 128460.

Almost surely, 2^61545840 is an apocalyptic number.

61545840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61545840 is an abundant number, since it is smaller than the sum of its proper divisors (129247008).

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

61545840 is a wasteful number, since it uses less digits than its factorization.

61545840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256457 (or 256451 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 33.

The square root of 61545840 is about 7845.1156779234. The cubic root of 61545840 is about 394.8203851432.

The spelling of 61545840 in words is "sixty-one million, five hundred forty-five thousand, eight hundred forty".