1493637661 has 2 divisors, whose sum is σ = 1493637662. Its totient is φ = 1493637660.

The previous prime is 1493637659. The next prime is 1493637689. The reversal of 1493637661 is 1667363941.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1218708100 + 274929561 = 34910^2 + 16581^2 .

It is a cyclic number.

It is not a de Polignac number, because 1493637661 - 2¹ = 1493637659 is a prime.

It is a super-3 number, since 3×1493637661³ (a number of 28 digits) contains 333 as substring.

Together with 1493637659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1493637601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 746818830 + 746818831.

It is an arithmetic number, because the mean of its divisors is an integer number (746818831).

Almost surely, 2^1493637661 is an apocalyptic number.

It is an amenable number.

1493637661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1493637661 is an equidigital number, since it uses as much as digits as its factorization.

1493637661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 46.

The square root of 1493637661 is about 38647.6087358584. The cubic root of 1493637661 is about 1143.0934910912.

The spelling of 1493637661 in words is "one billion, four hundred ninety-three million, six hundred thirty-seven thousand, six hundred sixty-one".