3653945978 has 4 divisors (see below), whose sum is σ = 5480918970. Its totient is φ = 1826972988.

The previous prime is 3653945951. The next prime is 3653945987. The reversal of 3653945978 is 8795493563.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8795493563 = 6011 ⋅1463233.

It can be written as a sum of positive squares in only one way, i.e., 3565642369 + 88303609 = 59713^2 + 9397^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 913486493 + ... + 913486496.

Almost surely, 2^3653945978 is an apocalyptic number.

3653945978 is a deficient number, since it is larger than the sum of its proper divisors (1826972992).

3653945978 is a wasteful number, since it uses less digits than its factorization.

3653945978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1826972991.

The product of its digits is 24494400, while the sum is 59.

The square root of 3653945978 is about 60447.8781927042. The cubic root of 3653945978 is about 1540.2363692395.

The spelling of 3653945978 in words is "three billion, six hundred fifty-three million, nine hundred forty-five thousand, nine hundred seventy-eight".