45643981 has 4 divisors (see below), whose sum is σ = 45835200. Its totient is φ = 45452764.

The previous prime is 45643967. The next prime is 45643987. The reversal of 45643981 is 18934654.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18934654 = 2 ⋅9467327.

It is a cyclic number.

It is not a de Polignac number, because 45643981 - 2¹³ = 45635789 is a prime.

It is a super-2 number, since 2×45643981² = 4166746003056722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (45643987) 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, 95251 + ... + 95728.

It is an arithmetic number, because the mean of its divisors is an integer number (11458800).

Almost surely, 2^45643981 is an apocalyptic number.

It is an amenable number.

45643981 is a deficient number, since it is larger than the sum of its proper divisors (191219).

45643981 is a wasteful number, since it uses less digits than its factorization.

45643981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191218.

The product of its digits is 103680, while the sum is 40.

The square root of 45643981 is about 6756.0329336083. The cubic root of 45643981 is about 357.3780202299.

The spelling of 45643981 in words is "forty-five million, six hundred forty-three thousand, nine hundred eighty-one".