40720521 has 4 divisors (see below), whose sum is σ = 54294032. Its totient is φ = 27147012.

The previous prime is 40720513. The next prime is 40720549. The reversal of 40720521 is 12502704.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 40720521 - 2³ = 40720513 is a prime.

It is a super-2 number, since 2×40720521² = 3316321661022882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (40720571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6786751 + ... + 6786756.

It is an arithmetic number, because the mean of its divisors is an integer number (13573508).

Almost surely, 2^40720521 is an apocalyptic number.

It is an amenable number.

40720521 is a deficient number, since it is larger than the sum of its proper divisors (13573511).

40720521 is a wasteful number, since it uses less digits than its factorization.

40720521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13573510.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 40720521 is about 6381.2632761860. The cubic root of 40720521 is about 344.0364375726.

The spelling of 40720521 in words is "forty million, seven hundred twenty thousand, five hundred twenty-one".