40921609 has 3 divisors (see below), whose sum is σ = 40928007. Its totient is φ = 40915212.

The previous prime is 40921603. The next prime is 40921619. The reversal of 40921609 is 90612904.

It is a happy number.

The square root of 40921609 is 6397.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 319225 + 40602384 = 565^2 + 6372^2 .

It is not a de Polignac number, because 40921609 - 2¹³ = 40913417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40921603) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 3199 + ... + 9595.

It is an arithmetic number, because the mean of its divisors is an integer number (13642669).

Almost surely, 2^40921609 is an apocalyptic number.

40921609 is the 6397-th square number.

40921609 is the 3199-th centered octagonal number.

It is an amenable number.

40921609 is a deficient number, since it is larger than the sum of its proper divisors (6398).

40921609 is an frugal number, since it uses more digits than its factorization.

40921609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12794 (or 6397 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 31.

The cubic root of 40921609 is about 344.6018202531.

The spelling of 40921609 in words is "forty million, nine hundred twenty-one thousand, six hundred nine".