1634640243 has 16 divisors (see below), whose sum is σ = 2304268800. Its totient is φ = 1027887840.

The previous prime is 1634640239. The next prime is 1634640247. The reversal of 1634640243 is 3420464361.

It is an interprime number because it is at equal distance from previous prime (1634640239) and next prime (1634640247).

It is not a de Polignac number, because 1634640243 - 2² = 1634640239 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1634640247) 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, 49563 + ... + 75668.

It is an arithmetic number, because the mean of its divisors is an integer number (144016800).

Almost surely, 2^1634640243 is an apocalyptic number.

1634640243 is a deficient number, since it is larger than the sum of its proper divisors (669628557).

1634640243 is a wasteful number, since it uses less digits than its factorization.

1634640243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125482.

The product of its (nonzero) digits is 41472, while the sum is 33.

The square root of 1634640243 is about 40430.6844240856. The cubic root of 1634640243 is about 1177.9876269763.

The spelling of 1634640243 in words is "one billion, six hundred thirty-four million, six hundred forty thousand, two hundred forty-three".