39899621 has 8 divisors (see below), whose sum is σ = 41347800. Its totient is φ = 38456320.

The previous prime is 39899617. The next prime is 39899623. The reversal of 39899621 is 12699893.

It can be written as a sum of positive squares in 4 ways, for example, as 83521 + 39816100 = 289^2 + 6310^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 39899621 - 2² = 39899617 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39899623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26201 + ... + 27681.

It is an arithmetic number, because the mean of its divisors is an integer number (5168475).

Almost surely, 2^39899621 is an apocalyptic number.

It is an amenable number.

39899621 is a deficient number, since it is larger than the sum of its proper divisors (1448179).

39899621 is a wasteful number, since it uses less digits than its factorization.

39899621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2439.

The product of its digits is 209952, while the sum is 47.

The square root of 39899621 is about 6316.6146787658. The cubic root of 39899621 is about 341.7088735749.

The spelling of 39899621 in words is "thirty-nine million, eight hundred ninety-nine thousand, six hundred twenty-one".