61213857 has 16 divisors (see below), whose sum is σ = 84188160. Its totient is φ = 39544400.

The previous prime is 61213849. The next prime is 61213891. The reversal of 61213857 is 75831216.

It is a cyclic number.

It is not a de Polignac number, because 61213857 - 2³ = 61213849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61213807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10132 + ... + 15002.

It is an arithmetic number, because the mean of its divisors is an integer number (5261760).

Almost surely, 2^61213857 is an apocalyptic number.

It is an amenable number.

61213857 is a deficient number, since it is larger than the sum of its proper divisors (22974303).

61213857 is a wasteful number, since it uses less digits than its factorization.

61213857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5004.

The product of its digits is 10080, while the sum is 33.

The square root of 61213857 is about 7823.9284889370. The cubic root of 61213857 is about 394.1092077048.

The spelling of 61213857 in words is "sixty-one million, two hundred thirteen thousand, eight hundred fifty-seven".