61541540 has 24 divisors (see below), whose sum is σ = 129480120. Its totient is φ = 24570368.

The previous prime is 61541539. The next prime is 61541563. The reversal of 61541540 is 4514516.

It can be written as a sum of positive squares in 4 ways, for example, as 15952036 + 45589504 = 3994^2 + 6752^2 .

It is a super-2 number, since 2×61541540² = 7574722291143200, which contains 22 as substring.

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, 9266 + ... + 14454.

It is an arithmetic number, because the mean of its divisors is an integer number (5395005).

Almost surely, 2^61541540 is an apocalyptic number.

It is an amenable number.

61541540 is an abundant number, since it is smaller than the sum of its proper divisors (67938580).

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

61541540 is a wasteful number, since it uses less digits than its factorization.

61541540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5791 (or 5789 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 61541540 is about 7844.8416172667. The cubic root of 61541540 is about 394.8111900068.

The spelling of 61541540 in words is "sixty-one million, five hundred forty-one thousand, five hundred forty".