1390611645 has 90 divisors (see below), whose sum is σ = 2672578062. Its totient is φ = 691628544.

The previous prime is 1390611619. The next prime is 1390611647. The reversal of 1390611645 is 5461160931.

1390611645 is a `hidden beast` number, since 1 + 3 + 9 + 0 + 6 + 1 + 1 + 645 = 666.

It can be written as a sum of positive squares in 9 ways, for example, as 1633284 + 1388978361 = 1278^2 + 37269^2 .

It is not a de Polignac number, because 1390611645 - 2¹⁵ = 1390578877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1390611647) by changing a digit.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 12757851 + ... + 12757959.

Almost surely, 2^1390611645 is an apocalyptic number.

1390611645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1390611645 is a deficient number, since it is larger than the sum of its proper divisors (1281966417).

1390611645 is an equidigital number, since it uses as much as digits as its factorization.

1390611645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 1390611645 is about 37290.9056607640. The cubic root of 1390611645 is about 1116.1827007509.

The spelling of 1390611645 in words is "one billion, three hundred ninety million, six hundred eleven thousand, six hundred forty-five".