1643460651 has 32 divisors (see below), whose sum is σ = 2929036800. Its totient is φ = 889691040.

The previous prime is 1643460641. The next prime is 1643460659. The reversal of 1643460651 is 1560643461.

It is a happy number.

1643460651 is a `hidden beast` number, since 1 + 6 + 43 + 4 + 606 + 5 + 1 = 666.

1643460651 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1643460651 - 2¹⁸ = 1643198507 is a prime.

It is a super-2 number, since 2×1643460651² = 5401925822770687602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1643460659) 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, 225240 + ... + 232421.

It is an arithmetic number, because the mean of its divisors is an integer number (91532400).

Almost surely, 2^1643460651 is an apocalyptic number.

1643460651 is a deficient number, since it is larger than the sum of its proper divisors (1285576149).

1643460651 is a wasteful number, since it uses less digits than its factorization.

1643460651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457696 (or 457690 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 1643460651 is about 40539.6182887802. The cubic root of 1643460651 is about 1180.1026079021.

The spelling of 1643460651 in words is "one billion, six hundred forty-three million, four hundred sixty thousand, six hundred fifty-one".