61856405 has 8 divisors (see below), whose sum is σ = 79937592. Its totient is φ = 45678528.

The previous prime is 61856369. The next prime is 61856437. The reversal of 61856405 is 50465816.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 108241 + 61748164 = 329^2 + 7858^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61856405 - 2¹² = 61852309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 475754 + ... + 475883.

It is an arithmetic number, because the mean of its divisors is an integer number (9992199).

Almost surely, 2^61856405 is an apocalyptic number.

61856405 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

61856405 is a deficient number, since it is larger than the sum of its proper divisors (18081187).

61856405 is a wasteful number, since it uses less digits than its factorization.

61856405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 951655.

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 61856405 is about 7864.8842966696. The cubic root of 61856405 is about 395.4833691542.

The spelling of 61856405 in words is "sixty-one million, eight hundred fifty-six thousand, four hundred five".