3661473978 has 24 divisors (see below), whose sum is σ = 7977030516. Its totient is φ = 1213747200.

The previous prime is 3661473961. The next prime is 3661473997. The reversal of 3661473978 is 8793741663.

It can be written as a sum of positive squares in 2 ways, for example, as 3653839809 + 7634169 = 60447^2 + 2763^2 .

It is a super-2 number, since 2×3661473978² = 26812783383142288968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 558663 + ... + 565178.

Almost surely, 2^3661473978 is an apocalyptic number.

3661473978 is an abundant number, since it is smaller than the sum of its proper divisors (4315556538).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3661473978 is a wasteful number, since it uses less digits than its factorization.

3661473978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1124030 (or 1124027 counting only the distinct ones).

The product of its digits is 4572288, while the sum is 54.

The square root of 3661473978 is about 60510.1146751516. The cubic root of 3661473978 is about 1541.2933950601.

It can be divided in two parts, 36614 and 73978, that added together give a cube (110592 = 48³).

The spelling of 3661473978 in words is "three billion, six hundred sixty-one million, four hundred seventy-three thousand, nine hundred seventy-eight".