61640923 has 4 divisors (see below), whose sum is σ = 62952480. Its totient is φ = 60329368.

The previous prime is 61640911. The next prime is 61640933. The reversal of 61640923 is 32904616.

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-61640923 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61640903) 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, 655708 + ... + 655801.

It is an arithmetic number, because the mean of its divisors is an integer number (15738120).

Almost surely, 2^61640923 is an apocalyptic number.

61640923 is a deficient number, since it is larger than the sum of its proper divisors (1311557).

61640923 is a wasteful number, since it uses less digits than its factorization.

61640923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1311556.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 61640923 is about 7851.1733517991. The cubic root of 61640923 is about 395.0236016448.

The spelling of 61640923 in words is "sixty-one million, six hundred forty thousand, nine hundred twenty-three".