69649015921 has 3 divisors (see below), whose sum is σ = 69649279833. Its totient is φ = 69648752010.

The previous prime is 69649015853. The next prime is 69649015973. The reversal of 69649015921 is 12951094696.

It is a happy number.

The square root of 69649015921 is 263911.

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 is not a de Polignac number, because 69649015921 - 2²⁹ = 69112145009 is a prime.

It is a super-2 number, since 2×69649015921² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (69649015991) 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, 131956 + ... + 395866.

It is an arithmetic number, because the mean of its divisors is an integer number (23216426611).

Almost surely, 2^69649015921 is an apocalyptic number.

69649015921 is the 263911-st square number.

69649015921 is the 131956-th centered octagonal number.

It is an amenable number.

69649015921 is a deficient number, since it is larger than the sum of its proper divisors (263912).

69649015921 is an frugal number, since it uses more digits than its factorization.

69649015921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527822 (or 263911 counting only the distinct ones).

The product of its (nonzero) digits is 1049760, while the sum is 52.

The spelling of 69649015921 in words is "sixty-nine billion, six hundred forty-nine million, fifteen thousand, nine hundred twenty-one".