1640942386 has 8 divisors (see below), whose sum is σ = 2468387484. Its totient is φ = 818146560.

The previous prime is 1640942377. The next prime is 1640942423. The reversal of 1640942386 is 6832490461.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1639035225 + 1907161 = 40485^2 + 1381^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1161435 + ... + 1162846.

Almost surely, 2^1640942386 is an apocalyptic number.

1640942386 is a deficient number, since it is larger than the sum of its proper divisors (827445098).

1640942386 is a wasteful number, since it uses less digits than its factorization.

1640942386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2324636.

The product of its (nonzero) digits is 248832, while the sum is 43.

The square root of 1640942386 is about 40508.5470734264. The cubic root of 1640942386 is about 1179.4995450335.

The spelling of 1640942386 in words is "one billion, six hundred forty million, nine hundred forty-two thousand, three hundred eighty-six".