101521399 has 16 divisors (see below), whose sum is σ = 124416000. Its totient is φ = 80855424.

The previous prime is 101521397. The next prime is 101521403. The reversal of 101521399 is 993125101.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 101521399 - 2¹ = 101521397 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 101521399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101521391) 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, 4002 + ... + 14800.

It is an arithmetic number, because the mean of its divisors is an integer number (7776000).

Almost surely, 2^101521399 is an apocalyptic number.

101521399 is a deficient number, since it is larger than the sum of its proper divisors (22894601).

101521399 is a wasteful number, since it uses less digits than its factorization.

101521399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10902.

The product of its (nonzero) digits is 2430, while the sum is 31.

The square root of 101521399 is about 10075.7827983735. The cubic root of 101521399 is about 466.5009486986.

The spelling of 101521399 in words is "one hundred one million, five hundred twenty-one thousand, three hundred ninety-nine".