21490689744 has 40 divisors (see below), whose sum is σ = 61686240320. Its totient is φ = 7163563104.

The previous prime is 21490689709. The next prime is 21490689797. The reversal of 21490689744 is 44798609412.

21490689744 is a `hidden beast` number, since 2 + 1 + 490 + 6 + 89 + 74 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24873052 + ... + 24873915.

It is an arithmetic number, because the mean of its divisors is an integer number (1542156008).

Almost surely, 2^21490689744 is an apocalyptic number.

21490689744 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21490689744 is an abundant number, since it is smaller than the sum of its proper divisors (40195550576).

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

21490689744 is a wasteful number, since it uses less digits than its factorization.

21490689744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49746984 (or 49746972 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The spelling of 21490689744 in words is "twenty-one billion, four hundred ninety million, six hundred eighty-nine thousand, seven hundred forty-four".