2154621757 has 4 divisors (see below), whose sum is σ = 2155655260. Its totient is φ = 2153588256.

The previous prime is 2154621751. The next prime is 2154621797. The reversal of 2154621757 is 7571264512.

2154621757 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 1189836036 + 964785721 = 34494^2 + 31061^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2154621757 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 (2154621751) 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, 513618 + ... + 517795.

It is an arithmetic number, because the mean of its divisors is an integer number (538913815).

Almost surely, 2^2154621757 is an apocalyptic number.

It is an amenable number.

2154621757 is a deficient number, since it is larger than the sum of its proper divisors (1033503).

2154621757 is a wasteful number, since it uses less digits than its factorization.

2154621757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1033502.

The product of its digits is 117600, while the sum is 40.

The square root of 2154621757 is about 46417.9034102145. The cubic root of 2154621757 is about 1291.5870451667.

The spelling of 2154621757 in words is "two billion, one hundred fifty-four million, six hundred twenty-one thousand, seven hundred fifty-seven".