61999331 has 4 divisors (see below), whose sum is σ = 62578872. Its totient is φ = 61419792.

The previous prime is 61999313. The next prime is 61999351. The reversal of 61999331 is 13399916.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61999331 is a prime.

It is a super-2 number, since 2×61999331² = 7687834088895122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61999351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 289610 + ... + 289823.

It is an arithmetic number, because the mean of its divisors is an integer number (15644718).

Almost surely, 2^61999331 is an apocalyptic number.

61999331 is a deficient number, since it is larger than the sum of its proper divisors (579541).

61999331 is a wasteful number, since it uses less digits than its factorization.

61999331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579540.

The product of its digits is 39366, while the sum is 41.

The square root of 61999331 is about 7873.9653923547. The cubic root of 61999331 is about 395.7877373987.

The spelling of 61999331 in words is "sixty-one million, nine hundred ninety-nine thousand, three hundred thirty-one".