1640214157 has 4 divisors (see below), whose sum is σ = 1711527840. Its totient is φ = 1568900476.

The previous prime is 1640214139. The next prime is 1640214187. The reversal of 1640214157 is 7514120461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7514120461 = 73 ⋅102933157.

It is a cyclic number.

It is not a de Polignac number, because 1640214157 - 2⁷ = 1640214029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640214187) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35656807 + ... + 35656852.

It is an arithmetic number, because the mean of its divisors is an integer number (427881960).

Almost surely, 2^1640214157 is an apocalyptic number.

It is an amenable number.

1640214157 is a deficient number, since it is larger than the sum of its proper divisors (71313683).

1640214157 is an equidigital number, since it uses as much as digits as its factorization.

1640214157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71313682.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 1640214157 is about 40499.5574914097. The cubic root of 1640214157 is about 1179.3250370037.

The spelling of 1640214157 in words is "one billion, six hundred forty million, two hundred fourteen thousand, one hundred fifty-seven".