1023651640 has 32 divisors (see below), whose sum is σ = 2512600560. Its totient is φ = 372236800.

The previous prime is 1023651637. The next prime is 1023651647. The reversal of 1023651640 is 461563201.

It is a junction number, because it is equal to n+sod(n) for n = 1023651599 and 1023651608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1023651647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1162801 + ... + 1163680.

Almost surely, 2^1023651640 is an apocalyptic number.

1023651640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1023651640 is an abundant number, since it is smaller than the sum of its proper divisors (1488948920).

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

1023651640 is a wasteful number, since it uses less digits than its factorization.

1023651640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2326503 (or 2326499 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 1023651640 is about 31994.5564119898. The cubic root of 1023651640 is about 1007.8225284894.

The spelling of 1023651640 in words is "one billion, twenty-three million, six hundred fifty-one thousand, six hundred forty".