61640836 has 6 divisors (see below), whose sum is σ = 107871470. Its totient is φ = 30820416.

The previous prime is 61640809. The next prime is 61640837. The reversal of 61640836 is 63804616.

It can be written as a sum of positive squares in only one way, i.e., 54671236 + 6969600 = 7394^2 + 2640^2 .

It is not an unprimeable number, because it can be changed into a prime (61640837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7705101 + ... + 7705108.

Almost surely, 2^61640836 is an apocalyptic number.

It is an amenable number.

61640836 is a deficient number, since it is larger than the sum of its proper divisors (46230634).

61640836 is a wasteful number, since it uses less digits than its factorization.

61640836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15410213 (or 15410211 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 61640836 is about 7851.1678112240. The cubic root of 61640836 is about 395.0234157993.

The spelling of 61640836 in words is "sixty-one million, six hundred forty thousand, eight hundred thirty-six".