61855997 has 4 divisors (see below), whose sum is σ = 70692576. Its totient is φ = 53019420.

The previous prime is 61855987. The next prime is 61856023. The reversal of 61855997 is 79955816.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61855997 - 2¹⁸ = 61593853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61855987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4418279 + ... + 4418292.

It is an arithmetic number, because the mean of its divisors is an integer number (17673144).

Almost surely, 2^61855997 is an apocalyptic number.

It is an amenable number.

61855997 is a deficient number, since it is larger than the sum of its proper divisors (8836579).

61855997 is an equidigital number, since it uses as much as digits as its factorization.

61855997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8836578.

The product of its digits is 680400, while the sum is 50.

The square root of 61855997 is about 7864.8583585466. The cubic root of 61855997 is about 395.4824996265.

The spelling of 61855997 in words is "sixty-one million, eight hundred fifty-five thousand, nine hundred ninety-seven".