1640430390 has 32 divisors (see below), whose sum is σ = 3938098176. Its totient is φ = 437329760.

The previous prime is 1640430383. The next prime is 1640430397. The reversal of 1640430390 is 930340461.

It is an interprime number because it is at equal distance from previous prime (1640430383) and next prime (1640430397).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640430397) 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, 212539 + ... + 220121.

It is an arithmetic number, because the mean of its divisors is an integer number (123065568).

Almost surely, 2^1640430390 is an apocalyptic number.

1640430390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1640430390 is an abundant number, since it is smaller than the sum of its proper divisors (2297667786).

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

1640430390 is a wasteful number, since it uses less digits than its factorization.

1640430390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14804.

The product of its (nonzero) digits is 7776, while the sum is 30.

The square root of 1640430390 is about 40502.2269758096. The cubic root of 1640430390 is about 1179.3768590548.

The spelling of 1640430390 in words is "one billion, six hundred forty million, four hundred thirty thousand, three hundred ninety".