7420663661 has 4 divisors (see below), whose sum is σ = 7425038172. Its totient is φ = 7416289152.

The previous prime is 7420663651. The next prime is 7420663669. The reversal of 7420663661 is 1663660247.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5588310025 + 1832353636 = 74755^2 + 42806^2 .

It is a cyclic number.

It is not a de Polignac number, because 7420663661 - 2¹⁸ = 7420401517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7420663669) 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, 2184710 + ... + 2188103.

It is an arithmetic number, because the mean of its divisors is an integer number (1856259543).

Almost surely, 2^7420663661 is an apocalyptic number.

It is an amenable number.

7420663661 is a deficient number, since it is larger than the sum of its proper divisors (4374511).

7420663661 is a wasteful number, since it uses less digits than its factorization.

7420663661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4374510.

The product of its (nonzero) digits is 217728, while the sum is 41.

The square root of 7420663661 is about 86143.2740322772. The cubic root of 7420663661 is about 1950.5073114429.

The spelling of 7420663661 in words is "seven billion, four hundred twenty million, six hundred sixty-three thousand, six hundred sixty-one".