40721640 has 64 divisors (see below), whose sum is σ = 122601600. Its totient is φ = 10820352.

The previous prime is 40721633. The next prime is 40721641. The reversal of 40721640 is 4612704.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 40721640.

It is not an unprimeable number, because it can be changed into a prime (40721641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52294 + ... + 53066.

It is an arithmetic number, because the mean of its divisors is an integer number (1915650).

Almost surely, 2^40721640 is an apocalyptic number.

40721640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

40721640 is an abundant number, since it is smaller than the sum of its proper divisors (81879960).

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

40721640 is a wasteful number, since it uses less digits than its factorization.

40721640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1226 (or 1222 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 40721640 is about 6381.3509541476. The cubic root of 40721640 is about 344.0395889177.

The spelling of 40721640 in words is "forty million, seven hundred twenty-one thousand, six hundred forty".