20261840240 has 20 divisors (see below), whose sum is σ = 47108778744. Its totient is φ = 8104736064.

The previous prime is 20261840237. The next prime is 20261840299. The reversal of 20261840240 is 4204816202.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×20261840240² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126636422 + ... + 126636581.

Almost surely, 2^20261840240 is an apocalyptic number.

20261840240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20261840240 is an abundant number, since it is smaller than the sum of its proper divisors (26846938504).

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

20261840240 is a wasteful number, since it uses less digits than its factorization.

20261840240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253273016 (or 253273010 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 29.

The spelling of 20261840240 in words is "twenty billion, two hundred sixty-one million, eight hundred forty thousand, two hundred forty".