61801918 has 4 divisors (see below), whose sum is σ = 92702880. Its totient is φ = 30900958.

The previous prime is 61801913. The next prime is 61801921. The reversal of 61801918 is 81910816.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61801913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15450478 + ... + 15450481.

It is an arithmetic number, because the mean of its divisors is an integer number (23175720).

Almost surely, 2^61801918 is an apocalyptic number.

61801918 is a deficient number, since it is larger than the sum of its proper divisors (30900962).

61801918 is a wasteful number, since it uses less digits than its factorization.

61801918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30900961.

The product of its (nonzero) digits is 3456, while the sum is 34.

The square root of 61801918 is about 7861.4195919058. The cubic root of 61801918 is about 395.3672128587.

The spelling of 61801918 in words is "sixty-one million, eight hundred one thousand, nine hundred eighteen".