1361639978 has 32 divisors (see below), whose sum is σ = 2210250240. Its totient is φ = 627041520.

The previous prime is 1361639977. The next prime is 1361640029. The reversal of 1361639978 is 8799361631.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1361639977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 369083 + ... + 372753.

It is an arithmetic number, because the mean of its divisors is an integer number (69070320).

Almost surely, 2^1361639978 is an apocalyptic number.

1361639978 is a deficient number, since it is larger than the sum of its proper divisors (848610262).

1361639978 is a wasteful number, since it uses less digits than its factorization.

1361639978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3962.

The product of its digits is 1469664, while the sum is 53.

The square root of 1361639978 is about 36900.4062037263. The cubic root of 1361639978 is about 1108.3768115657.

The spelling of 1361639978 in words is "one billion, three hundred sixty-one million, six hundred thirty-nine thousand, nine hundred seventy-eight".