21061649140 has 48 divisors (see below), whose sum is σ = 50607228672. Its totient is φ = 7212669696.

The previous prime is 21061649123. The next prime is 21061649159. The reversal of 21061649140 is 4194616012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21061649096 and 21061649105.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32209 + ... + 207751.

It is an arithmetic number, because the mean of its divisors is an integer number (1054317264).

Almost surely, 2^21061649140 is an apocalyptic number.

21061649140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21061649140 is an abundant number, since it is smaller than the sum of its proper divisors (29545579532).

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

21061649140 is a wasteful number, since it uses less digits than its factorization.

21061649140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176416 (or 176414 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The spelling of 21061649140 in words is "twenty-one billion, sixty-one million, six hundred forty-nine thousand, one hundred forty".