61998558 has 32 divisors (see below), whose sum is σ = 138205440. Its totient is φ = 18426240.

The previous prime is 61998551. The next prime is 61998571. The reversal of 61998558 is 85589916.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a self number, because there is not a number n which added to its sum of digits gives 61998558.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61998551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14058 + ... + 17933.

It is an arithmetic number, because the mean of its divisors is an integer number (4318920).

Almost surely, 2^61998558 is an apocalyptic number.

61998558 is an abundant number, since it is smaller than the sum of its proper divisors (76206882).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61998558 is a wasteful number, since it uses less digits than its factorization.

61998558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32032.

The product of its digits is 777600, while the sum is 51.

The square root of 61998558 is about 7873.9163063878. The cubic root of 61998558 is about 395.7860925143.

The spelling of 61998558 in words is "sixty-one million, nine hundred ninety-eight thousand, five hundred fifty-eight".