615921401 has 4 divisors (see below), whose sum is σ = 637160100. Its totient is φ = 594682704.

The previous prime is 615921391. The next prime is 615921413. The reversal of 615921401 is 104129516.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 489471376 + 126450025 = 22124^2 + 11245^2 .

It is a cyclic number.

It is not a de Polignac number, because 615921401 - 2¹⁰ = 615920377 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 21238669 = 615921401 / (6 + 1 + 5 + 9 + 2 + 1 + 4 + 0 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (615921421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10619306 + ... + 10619363.

It is an arithmetic number, because the mean of its divisors is an integer number (159290025).

Almost surely, 2^615921401 is an apocalyptic number.

It is an amenable number.

615921401 is a deficient number, since it is larger than the sum of its proper divisors (21238699).

615921401 is a wasteful number, since it uses less digits than its factorization.

615921401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21238698.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 615921401 is about 24817.7638194903. The cubic root of 615921401 is about 850.8279825913.

The spelling of 615921401 in words is "six hundred fifteen million, nine hundred twenty-one thousand, four hundred one".