1640377521 has 32 divisors (see below), whose sum is σ = 2567360000. Its totient is φ = 1032275664.

The previous prime is 1640377513. The next prime is 1640377537. The reversal of 1640377521 is 1257730461.

It is a happy number.

1640377521 is a `hidden beast` number, since 1 + 64 + 0 + 3 + 77 + 521 = 666.

It is not a de Polignac number, because 1640377521 - 2³ = 1640377513 is a prime.

It is a super-2 number, since 2×1640377521² = 5381676822804210882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640377421) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 139530 + ... + 150828.

It is an arithmetic number, because the mean of its divisors is an integer number (80230000).

Almost surely, 2^1640377521 is an apocalyptic number.

It is an amenable number.

1640377521 is a deficient number, since it is larger than the sum of its proper divisors (926982479).

1640377521 is a wasteful number, since it uses less digits than its factorization.

1640377521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11610 (or 11604 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 36.

The square root of 1640377521 is about 40501.5743027354. The cubic root of 1640377521 is about 1179.3641889763.

The spelling of 1640377521 in words is "one billion, six hundred forty million, three hundred seventy-seven thousand, five hundred twenty-one".