20491740 has 36 divisors (see below), whose sum is σ = 62158824. Its totient is φ = 5464416.

The previous prime is 20491739. The next prime is 20491753. The reversal of 20491740 is 4719402.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×20491740² = 839822816455200, which 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 11 ways as a sum of consecutive naturals, for example, 56742 + ... + 57101.

It is an arithmetic number, because the mean of its divisors is an integer number (1726634).

Almost surely, 2^20491740 is an apocalyptic number.

20491740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20491740 is an abundant number, since it is smaller than the sum of its proper divisors (41667084).

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

20491740 is a wasteful number, since it uses less digits than its factorization.

20491740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113858 (or 113853 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 20491740 is about 4526.7803127609. The cubic root of 20491740 is about 273.6484204341.

The spelling of 20491740 in words is "twenty million, four hundred ninety-one thousand, seven hundred forty".